text:
WOODSTOCK - A McHenry County judge told a 17-year-old girl she should have left the area rather than throwing a rock at three boys who were yelling homosexual slurs at her friend.
But Judge Charles Weech acquitted Kimberlynn S. Bolanos of misdemeanor criminal damage to property today after ruling that she twice threw a rock in self-defense. The rock broke the rear-side window of the trio's car on July 8 and caused less than $300 in damage.
"Two wrongs don't make a right," Weech said. "And that's what happened."
Bolanos, formerly of Crystal Lake, testified that she and a 15-year-old boy were walking north on Green Street in McHenry when three boys, one with a megaphone, shouted derogatory terms for gay men at them from a car.
When the car passed them a second time and the harassment resumed, Bolanos testified that she threatened to throw a rock at the car if it passed them a third time. Bolanos said one of the three boys got out of the car and repeatedly called her a name, which two of the boys denied.
But the car returned again, coming so close to Bolanos that she said she had to jump back to avoid being hit. She said she threw the rock twice "just because I was scared." The first toss missed; the second broke the window.
The car's driver, a 16-year-old McHenry boy, chased Bolanos' 15-year-old friend. She said the older boy grabbed and threatened the 15-year-old, but the 16-year-old testified that he only approached the boy and explained that he called police about the broken window.
Defense attorney Dan Hofmann argued that the three boys' conduct amounted to a felony hate crime, because they committed disorderly conduct or assault because of the 15-year-old's sexual orientation or perceived sexual orientation.
"They are shouting out of a megaphone - a megaphone - to make no mistake they were committing a hate crime," Hofmann said.
But prosecutors argued that Bolanos was not acting in self-defense, emphasizing discrepancies between her and the 15-year-old's accounts. They argued she was taking the law into her own hands out of annoyance and frustration.
"A 17-year-old [decided] she didn't like what was going on," Assistant State's Attorney Robert Windon said. "She was going to do something about it."
The three boys testified that their car only passed the two pedestrians once. They denied revving the car's engine in a threatening way or almost running Bolanos over.
But Weech said he found Bolanos' and her friend's testimony more credible than the trio's. The three teens in the car had ample opportunity to discuss the incident before the trial this week, Weech said. At Bolanos' request, Weech, rather than a jury, evaluated the evidence and rendered a verdict.
"It's obvious to me by the carefulness of their words that they had orchestrated to some extent their testimony," Weech said.
Court records indicate the 16-year-old driver was charged was disorderly conduct, an ordinance violation, which was later dropped. It wasn't clear whether misdemeanor or felony charges were filed against the three, because juvenile records are not available to the public.
Girl acquitted of smashing car window
WOODSTOCK - A McHenry County judge told a 17-year-old girl she should have left the area rather than throwing a rock at three boys who were yelling homosexual slurs at her friend.


text:
I'm not always comfortable with phrasal verbs. I find that Americans use a lot of phrasal verbs than say people from UK -- I might be completely wrong though.
What I find most difficult with phrasal verbs is to know when it is appropriate to use them - like is this phrasal verb formal or informal. So for this very reason, I tend to avoid using them.
I think it's definitely far easier for native speakers because of familiarity with cultural settings in which the verbs arose.
My question is whether there are any tips for non-natives to not just know what phrasal verbs are, but also to understand the context of how they are used; and what such tips might be.

subset: commoncrawl


text:
Guide Contents
Internetworking Basics
LAN Technologies
WAN Technologies
Internet Protocols
Bridging and Switching
Network Management
Voice/Data Integration Technologies
Cable Access Technologies
Dial-up Technology
Security Technologies
Quality of Service Networking
Network Caching Technologies
IBM Network Management
Multiservice Access Technologies
1 Types of Wireless Technology
1.1 Table: Different Types of Wireless Technologies
1.2 Base Station
2 Introduction to QAM
2.1 Figure: Error Rates for PSK and QAM Systems
2.2 Figure: BER Against Signal-to-Noise for Coded and Uncoded Data Streams
2.3 Advanced Signaling Techniques Used to Mitigate Multipath
2.4 QAM with DFE
2.4.1 Figure: Computational Complexity of QAM Versus OFDM
3 Spread Spectrum
3.3.1 Figure: Example of OFDM Tones
3.4.1 Figure: Spectrum Technology
4 Benefits of Using Wireless Solutions
5 Earth Curvature Calculation for Line-of-Sight Systems
5.1 Table: Wireless Distance Calculations
6 Non-Line-of-Sight Wireless: Overcoming Multipath in Non-Line-of-Sight High-Speed
6.1 Microwave Communication Links
6.2 What Is Multipath?
6.2.1 Figure: Multipath Reception
6.2.2 Figure: Typical Multipath Example
6.3 Multipath in Non-LOS Environments
7 Elements of a Total Network Solution
7.1 Premises Networks
7.2 Access Networks
7.3 Core Networks
7.4 Network Management
7.5 Deployment
7.6 Billing and Management of Wireless Systems
Contents 1
Contents 2
The process by which radio waves are propagated through the air, the amount of data carried, immunity to
interference from internal and external sources, and a host of other characteristics varies from technology to
Protocol - ATM or IP
Connection type - Point-to-Point (P2P) or multipoint (P2MP) connections
Spectrum - Licensed or unlicensed
Table: Different Types of Wireless Technologies lists the different wireless technologies.
Broadband Narrowband
WAN WAN and WLAN
Licensed Unlicensed
Digital Analog
Line-of-site Non-line-of-site
Simplex Half-/full-Duplex
Point-to-point Multipoint
Base Station
The base station (also referred to as the hub or the cell site) is the central location that collects all traffic to
and from subscribers within a cell. The indoor base station equipment consists of channel groups. The
channel groups each connect to the existing network, typically with a DS-3 with ATM signaling. The
function of the channel group is to effectively act as a high-speed radio modem for the DS-3 traffic. The
outdoor base station equipment (Tx/Rx node) modules are located on a tower or a rooftop mount and consist
of a frequency translation hardware and transmitters/receivers. The Tx/Rx node delivers and collects all the
traffic to and from subscribers within a cell or a sector. Additionally, the Tx/Rx node equipment translates
the channel group output into the appropriate frequency for over-the-air transmission. Multiple channel
groups are used in each sector to meet the traffic demands, thus providing a highly scalable architecture.
Introduction to QAM
Many modern fixed microwave communication systems are based on quadrature amplitude modulation
(QAM). These systems have various levels of complexity.
Simpler systems such as phase shift keying (PSK) are very robust and easy to implement because they have
low data rates. In PSK modulation, the shape of the wave is modified in neither amplitude nor frequency, but
rather in phase. The phase can be thought of as a shift in time. In binary phase shift keying (BPSK), the
phases for the sine wave start at either 0 or 1/4. In BPSK modulation, only 1 bit is transmitted per cycle
(called a symbol). In more complex modulation schemes, more than 1 bit is transmitted per symbol. The
modulation scheme QPSK (quadrature phase shift keying) is similar to the BPSK. However, instead of only
two separate phase states, QPSK uses four (0, 1/2 , , and 3/2 ), carrying 2 bits per symbol. Like BPSK,
QPSK is used because of its robustness. However, because it modulates only 2 bits per symbol, it still is not
very efficient for high-speed commun-ications. Hence, higher bit rates require the use of significant
Even though QPSK uses no state changes in amplitude, it is sometimes referred to as 4-QAM. When four
levels of amplitude are combined with the four levels of phase, we get 16-QAM. In 16 QAM, 2 bits are
encoded on phase changes, and 2 bits are encoded on amplitude changes, yielding a total of 4 bits per
In Figure: Error Rates for PSK and QAM Systems, each unique phase is spaced equally in both the I and Q
coordinates. The angle of rotation indicates the phase, and the distance from the center point indicates the
amplitude. This approach to modulation can be expanded out to 64-QAM and 256-QAM or higher. Although
64-QAM is very popular in both cable and wireless broadband products, 256-QAM is also being tested. The
higher the density in QAM, the higher a signal-to-noise (s/n) ratio must be maintained to meet the required
bit-error rates (BERs).
How the data is encoded also plays an important part in the equation. The data is usually scrambled, and a
significant amount of forward error correction (FEC) data is also transmitted. Therefore, the system can
recover those bits that are lost because of noise, multipath, and interference. A significant improvement in
BER is achieved using FEC for a given SNR at the receiver. (See the Figure: BER Against Signal-to-Noise
for Coded and Uncoded Data Streams.)
Introduction to QAM 4
Figure: BER Against Signal-to-Noise for Coded and Uncoded Data Streams
Several techniques have been used to make digital modulation schemes more robust: QAM with decision
feedback equalization (DFE), direct sequence spread spectrum (DSSS), frequency-division multiplexing
(FDM), and orthogonal frequency-division multiplexing (OFDM).
In wireless QAM systems, DFE is used to mitigate the effects of the intersymbol interference (ISI) caused by
multipath. When delay spread is present, the echoes of previous symbols corrupt the sampling instant for the
current symbol. The DFE filter oversamples the incoming signal and filters out the echoed carriers. The
complexity of DFE schemes causes them not to scale with increases in bandwidth. The complexity of the
DFE filter (number of taps) is proportional to the size of the delay spread. The number of required taps is
proportional to the delay spread (in seconds) multiplied by the symbol rate.
For a QAM-based wireless system transmitting in the MMDS band (6-MHz-wide channel) to survive a
4-sec delay spread, the number of taps required would equal 24. To equalize a system with 24 taps, a DFE
system would need 72 feedforward and 24 feedback taps. In addition to the number of taps needed, the
complexity of the math needed for each tap increases with the number of taps. Therefore, the increase in
complexity becomes an exponential function of the bandwidth of the carrier signal.
Figure: Computational Complexity of QAM Versus OFDM compares the complexity rate of QAM/DFE and
OFDM. Orthogonal frequency-division multiplexing (OFDM) is discussed later in this paper.
Figure: BER Against Signal-to-Noise for Coded and Uncoded Data Streams 5
Spread Spectrum
Spread spectrum is a method commonly used to modulate the information into manageable bits that are sent
over the air wirelessly. Spread spectrum was invented by Heddy Lamar, a film actress who still retains the
patent to this day and was the relatively recent recipient of a governmental award for this accomplishment.
Essentially, spread spectrum refers to the concept of splitting information over a series of radio channels or
frequencies. Generally, the number of frequencies is in the range of about 70, and the information is sent over
all or most of the frequencies before being demodulated, or combined at the receiving end of the radio
DSSS typically has better performance, while FHSS is typically more resilient to interference.
A commonly used analogy to understand spread spectrum is that of a series of trains departing a station at the
same time. The payload is distributed relatively equally among the trains, which all depart at the same time.
Upon arrival at the destination, the payload is taken off each train and is collated. Duplications of payload are
common to spread spectrum so that when data arrives excessively corrupted, or fails to arrive, the
redundancies inherent to this architecture provide a more robust data link.
Direct sequence spread spectrum (DSSS) is a signaling method that avoids the complexity and the need for
equalization. Generally, a narrowband QPSK signal is used. This narrowband signal is then multiplied (or
spread) across a much wider bandwidth. The amount of spectrum needed is expressed as: 10(SNR/10)
narrowband symbol rate.
Therefore, if a SNR of 20 dB is required to achieve the appropriate BER, the total spread bandwidth needed
to transmit a digital signal of 6 Mbps equals 600 MHz.
This is not very bandwidth-efficient. In addition, the sampling rate for the receiver needs to be about 100
times the data rate. Therefore, for this hypothetical system, the sampling rate would also need to be 600
megasamples per second.
Code division multiple access (CDMA) is used to allow several simultaneous transmissions to occur. Each
data stream is multiplied with a pseudorandom noise code (PN code). All users in a CDMA system use the
same frequency band. Each signal is spread out and layered on top of each other and is overlaid using code
spreading in the same time slot. The transmitted signal is recovered by using the PN code. Data transmitted
by other users looks like white noise and drops out during the reception phase. Any narrowband noise is
dispersed during the de-spreading of the data signal. The advantage of CMDA is that the amount of
bandwidth required is now shared over several users. However, in systems in which there are multiple
transmitters and receivers, proper power management is needed to ensure that one user does not overpower
other users in the same spectrum. These power management issues are mainly confined to CMDA
With the FHSS architecture, the trains leave in a different order-that is, not sequentially from Train 1 to Train
N. In the best of FHSS systems, trains that run into interference are not sent out again until the interference
abates. In FHSS systems, certain frequencies (channels) are avoided until the interference abates.
Interference tends to cover more than one channel at a time. Therefore, DSSS systems tend to lose more data
from interference as the data sent out is done so over sequential channels. FHSS systems hop between
channels in nonsequential order. The best of FHSS systems adjust channel selection so that highly interfered
channels are avoided as measured by excessively low bit error rates. Either approach is appropriate and
depends on customer requirements, with the selection criteria primarily being that of a severe multipath or
interfering RF environment.
In a frequency-division multiplexing (FDM) system, the available bandwidth is divided into multiple data
carriers. The data to be transmitted is then divided among these subcarriers. Because each carrier is treated
independently of the others, a frequency guard band must be placed around it. This guard band lowers the
bandwidth efficiency. In some FDM systems, up to 50 percent of the available bandwidth is wasted. In most
FDM systems, individual users are segmented to a particular subcarrier; therefore, their burst rate cannot
exceed the capacity of that subcarrier. If some subcarriers are idle, their bandwidth cannot be shared with
other subcarriers.
In OFDM (see Figure: Example of OFDM Tones), multiple carriers (or tones) are used to divide the data
across the available spectrum, similar to FDM. However, in an OFDM system, each tone is considered to be
orthogonal (independent or unrelated) to the adjacent tones and, therefore, does not require a guard band.
Because OFDM requires guard bands only around a set of tones, it is more efficient spectrally than FDM.
Because OFDM is made up of many narrowband tones, narrowband interference will degrade only a small
portion of the signal and has no or little effect on the remainder of the frequency components.
Spread Spectrum 7
OFDM systems use bursts of data to minimize ISI caused by delay spread. Data is transmitted in bursts, and
each burst consists of a cyclic prefix followed by data symbols. An example OFDM signal occupying 6 MHz
is made up of 512 individual carriers (or tones), each carrying a single QAM symbol per burst. The cyclic
prefix is used to absorb transients from previous bursts caused by multipath signals. An additional 64
symbols are transmitted for the cyclic prefix. For each symbol period, a total of 576 symbols are transmitted
by only 512 unique QAM symbols per burst. In general, by the time the cyclic prefix is over, the resulting
waveform created by the combining multipath signals is not a function of any samples from the previous
burst. Hence, there is no ISI. The cyclic prefix must be greater than the delay spread of the multipath signals.
In a 6-MHz system, the individual sample rate is 0.16 secs. Therefore, the total time for the cyclic prefix is
10.24 secs, greater than the anticipated 4 secs delay spread.
In addition to the standard OFDM principles, the use of spatial diversity can increase the system's tolerance
to noise, interference, and multipath. This is referred to as vectored OFDM, or VOFDM (see Figure:
Spectrum Technology). Spatial diversity is a widely accepted technique for improving performance in
multipath environments. Because multipath is a function of the collection of bounced signals, that collection
is dependent on the location of the receiver antenna. If two or more antennae are placed in the system, each
would have a different set of multipath signals. The effects of each channel would vary from one antenna to
the next, so carriers that may be unusable on one antenna may become usable on another. Antenna spacing is
at least ten times the wavelength.
Significant gains in the S/N are obtained by using multiple antennae. Typically, a second antenna adds about
3 dB in LOS and up to 10 dB in non-LOS environments.
Completes the access technology portfolio - Customers commonly use more than one access
technology to service various parts of their network and during the migration phase of their
networks, when upgrading occurs on a scheduled basis. Wireless enables a fully comprehensive
access technology portfolio to work with existing dial, cable, and DSL technologies.
Goes where cable and fiber cannot - The inherent nature of wireless is that it doesn't require wires
or lines to accommodate the data/voice/video pipeline. As such, the system will carry information
across geographical areas that are prohibitive in terms of distance, cost, access, or time. It also
sidesteps the numerous issues of ILEC colocation.
Although paying fees for access to elevated areas such as masts, towers, and building tops is not
unusual, these fees, the associated logistics, and contractual agreements are often minimal compared
to the costs of trenching cable.
Involves reduced time to revenue - Companies can generate revenue in less time through the
deployment of wireless solutions than with comparable access technologies because a wireless
system can be assembled and brought online in as little as two to three hours.
This technology enables service providers to sell access without having to wait for cable-trenching
operations to complete or for incumbent providers to provide access or backhaul.
Provides broadband access extension - Wireless commonly both competes with and complements
existing broadband access. Wireless technologies play a key role in extending the reach of cable,
fiber, and DSL markets, and it does so quickly and reliably. It also commonly provides a competitive
alternative to broadband wireline or provides access in geographies that don't qualify for loop access.
The industry standard is to keep 60 percent of the first Fresnel zone clear from obstacles. Therefore, the
result of this calculation can be reduced by up to 60 percent without appreciable interference. This
calculation should be considered as a reference only and does not account for the phenomenon of refraction
from highly reflective surfaces.
Since the beginning of development of microwave wireless transmission equipment, manufacturers and
operators have tried to mitigate the effects of reflected signals associated with signal propagation. These
reflections are called multipath. In real-world situations, microwave systems involve careful design to
overcome the effects of multipath. Most existing multipath mitigation approaches fall well short of the full
reliable information rate potential of many wireless communications systems. This section discusses how to
Digital microwave systems fall into two categories: wavelengths less than 10 GHz and wavelengths greater
than 10 GHz (referred to as millimeterwave). Several bands exist below 10 GHz for high-speed
transmissions. These may be licensed bands, such as MMDS (2.5 GHz), or unlicensed bands, such as U-NII
(5.7 GHz). Bands that are below 10 GHz have long propagation distances (up to 30 miles). They are only
mildly affected by climatic changes such as rain. These frequencies are generally not absorbed by objects in
the environment. They tend to bound and thus result in a high amount of multipath.
Bands over 10 GHz, such as 24 GHz, LMDS (28 GHz), and 38 GHz, are very limited to distance (less than 5
miles). They are also quite susceptible to signal fades attributed to rain. Multipath tends not to be an issue
because the transmission distances are less and because most of the multipath energy is absorbed by the
physical environment. However, when these frequencies are used in highly dense urban areas, the signals
tend to bounce off objects such as metal buildings or metalized windows. The use of repeaters can add to the
multipath propagation by delaying the received signal.
What Is Multipath?
Multipath is the composition of a primary signal plus duplicate or echoed images caused by reflections of
signals off objects between the transmitter and the receiver. In Figure: Multipath Reception, the receiver
hears the primary signal sent directly from the transmission facility, but it also sees secondary signals that are
bounced off nearby objects.
These bounced signals will arrive at the receiver later than the incident signal. Because of this misalignment,
the out-of-phase signals will cause intersymbol interference or distortion of the received signal. Although
most of the multipath is caused by bounces off tall objects, multipath can also occur from bounces off low
objects such as lakes and pavement.
The actual received signal is a combination of a primary signal and several echoed signals. Because the
distance traveled by the original signal is shorter than the bounced signal, the time differential causes two
signals to be received. These signals are overlapped and combined into a single one. In real life, the time
between the first received signal and the last echoed signal is called the delay spread, which can be as high as
4 sec.
In analog systems such as television, this multipath situation can actually be seen by the human eye.
Sometimes there is a ghost image on your television, and no matter how much you adjust the set, the image
does not go away. In these analog systems, this is an annoyance. In digital systems, it usually corrupts the
data stream and causes loss of data or lower performance. Correction algorithms must be put in place to
compensate for the multipath, resulting in a lower available data rate.
In digital systems, the input signal is sampled at the symbol rate. The echoed signal actually interferes with
the reception of the second symbol, thus causing intersymbol interference (ISI). This ISI is the main result of
multipath, and digital systems must be designed to deal with it.
In LOS environments, multipath is usually minor and can be overcome easily. The amplitudes of the echoed
signals are much smaller than the primary one and can be effectively filtered out using standard equalization
techniques. However, in non-LOS environments, the echoed signals may have higher power levels because
the primary signal may be partially or totally obstructed, and generally because more multipath is present.
This makes the equalization design more difficult.
In all the previous discussions, the multipath has been a semifixed event. However, other factors such as
moving objects enter into play. The particular multipath condition changes from one sample period to the
next. This is called time variation. Digital systems must be capable of withstanding fast changes in the
multipath conditions, referred to as fast fading. To deal with this condition, digital systems need fast AGC
circuits. Adaptive equalizers, discussed next, need fast training times.
Premises networks
Access networks
Core networks
Network management
A fully comprehensive wireless solution must also include the issues of deployment, maintenance, legacy,
migration, and value propositions. The scope of what comprises a fully comprehensive solution can readily
exceed these items.
Premises Networks
Premises networks are the voice, data, or video distribution networks that exist or will exist within the
subscriber premises. Typical points of demarcation between the access and premises networks for purposes
of this discussion include channel banks, PBXs, routers, or multiservice access devices.
Customer premises equipment receives signals from the hub, translates them into customer-usable data, and
transmits returning data back to the hub. The transmitter, the receiver, and the antenna are generally housed
in a compact rooftop unit (RTU) that is smaller than a satellite TV minidish. It is mounted on the subscriber's
roof in a location where it will have a clear line of sight to the nearest LMDS hub site. Installation includes
semiprecision pointing to ensure maximum performance of the RF link.
The indoor unit, the network interface unit (NIU), does the modulation, demodulation, in-building wire-line
interface functions, and provides an intermediate frequency to the RTU. Many interfaces required by end
customer equipment require the NIU to have a breadth of physical and logical interfaces. The NIUs are
designed to address a range of targeted subscribers whose connectivity requirements may range from T1/E1,
POTS, Ethernet, or any other standard network interface. These interfaces are provided by the NIU with
interworking function (IWF) cards. Different types of IWF cards are required in the NIU to convert the
inputs into ATM cells and provide the appropriate signaling. Common IWFs include 10BaseT, T1/E1 circuit
emulation, and others. The NIU also has an IF that is translated by the CPE RTU.
Access Networks
The access networks are the transport and distribution networks that bridge the premises network and the
core network demarcation points. For purposes of this discussion, the primary means of providing the
transport from an access network point-of-presence (POP) to the premises is radio and the distribution
between access network POPs is either fiber or radio.
Core Networks
The core networks are the public or private backbone networks that, in a general sense, will be utilized by the
access network operators to connect their multitude of regionally dispersed POPs and to interconnect to
public service provider network elements. For purposes of this discussion, the point of demarcation between
the access network and the core network is a core switch that serves as an upstream destination point for a
multitude of access network branches or elements.
Network Management
The glue that ties all the network elements together and supports the key information processing tasks that
make a business run effectively is performed by the Network Management System (NMS) inclusive of
Operational Support System (OSS) functionality. In its full implementation, the NMS is an exceptionally
complex set of moderately to highly integrated software platforms. For the purposes of this document, the
element managers necessary within each system-level piece of the access network are assumed, but the
overarching NMS is beyond the intended scope of this document.
Ideally, the NMS should provide end-to-end functionality throughout both the wireless and wireline elements
of the network, including the backbone and the customer premises. A network management system performs
service, network, and element management across multivendor and multitechnology networks, including
Topology management
Connectivity management
Event management
The functions of the network management system can be further outlined as follows:
Integrated topology map that displays an entire set of nodes and links in the network, shown with
mapped alarms
Store of network-wide physical (nodes/links) and logical topology (circuits/PVCs) for inventory
Customer care interface to provide network and end-user status
Performance statistics on PCR, SCR, MBS, CDVT, and network/link status
SLA reporting with customer partitioning, and alerting of customer violations
Alarm correlation and root-cause analysis
Network simulation to test whether a problem was completely corrected
Trouble ticketing/workforce management
Performance reports based on statistics collected, with customer and network views
Usage-based billing for ATM connections
Read-only CNM for viewing network and connection
As stated previously, tier 1 customers will utilize Cisco's ecosystem of deployment partners. Deployment for
systems covering BTA, MTA, or nationwide footprints requires the following areas of expertise and
The issue of billing and network management is a considerable one. In the most general terms, you should
consider the wireless links as a network section managed by the standard Cisco IOS and SNMP tools.
Network Management 14
Accordingly, key customer items such as billing, dynamic host control, testing, and configuration are
managed remotely with standard router tools, as indicated in Figure: Management Interfaces.
Example Implementation
Cisco's MMDS/U-NII system is designed with the following objectives:
For a service provider to offer differentiated services via wireless access, the wireless access system
should offer higher capacity than alternative access technologies.
The capacity of the system is increased by three items:
A highly efficient physical layer that is robust to interference, resulting in high bandwidth
efficiency per sector
A statistically efficient industry standard Medium Access Control (MAC) protocol that
delivers quality of service (QoS)
A multicellular system
Large bandwidth enables differentiated services such as Voice over IP (VoIP) now, and interactive
video in the future, both with QoS.
A multitiered CPE approach, satisfying the needs of small and medium businesses (SMB), small
office/home office (SOHO) applications, and residential customers.
Ease of base installation and back-haul.
Ease of provisioning and network management.
Table: Features and Benefits of Wireless Communication summarizes the advantages of the proposed
Shared-bandwidth system Shared bandwidth among many small and medium businesses
Dedicated high-bandwidth
High data rate (22 to 44 Mbps)
Third-generation microwave
technology Tolerant of narrow-band interference
Partners capable of supplying outdoor unit (ODU), antenna, cable, and all
other components outside the router
Open interfaces
Availability of in-country manufacturers as partners
Video over IP
Queuing features
Traffic policies
Competitively priced
Cost-effective solution
Reduced training time
IP Point-to-MultiPoint Architecture
The point-to-multipoint (P2MP) system consists of a hub, or head end (HE), or a base station (BS), which
serves several sectors in the cell. Each sector consists of one radio communicating with many customers.
The head end is an outdoor unit, or transverter, connected to a wireless modem card inside a Cisco UBR7246
or 7223 router.
At the customers' premises is another transverter, which is connected to a wireless network module in a
Integrated end-to-end solution (one box, one management and provisioning platform)
Complete multiservice offering (Voice over IP, data, Video over IP)
Scalability and flexibility (scalable head end and CPE offerings)
Enabled for non-line-of-sight (substantially better coverage)
Native IP packet transport
Part of an overall standards-based strategy to provide many Cisco hosts and many frequency bands
on a global basis
applications, as shown in Figure: Basic Components of the P2MP Base Station (Head End, Hub).
Figure: Basic Components of the P2MP Base Station (Head End, Hub)
The P2MP wireless router will be an integrated solution. At the base station (or head end, or hub), it will
consist of a base universal router (UBR 7246 or UBR7223), a wireless modem card, an outdoor unit (ODU)
for the appropriate frequency band, cables, and antenna subsystems, as shown in Figure: The Cisco MMDS
Broadband Wireless Access System.
IP Point-to-MultiPoint Architecture 19
At the small business customer premises, the system consists of a network module in a 3600-family router,
with an outdoor unit (ODU) and antenna. This CPE equipment is simpler and, therefore, less expensive than
the head end (HE) equipment. The 3600 family has a wide variety of interfaces to match all types of
customer equipment.
At the SOHO or telecommuter customer premises, the system consists of a network module in a 2600- or
900-family router, with an outdoor unit (ODU) and an antenna. This CPE equipment is simpler and,
therefore, less expensive than the head end (HE) equipment. The 2600 and 900 families have a wide variety
of interfaces to match all types of customer equipment. A consumer unit by one or more of Cisco's ecosystem
partners is expected by the first quarter of 2001.
These wireless broadband routers (WBBR) are then used to blanket an urban area by dividing the business
district into small cells.
The product will also be capable of working as a single cell-that is, one hub serving an entire business district
in a cell of radius less than 45-miles, because the low frequencies in the MMDS band are not impacted by
rain. However, a single cell does not have the revenue potential of small cells. See the section "Title" for the
revenue generation potential of these two alternatives.
Technology has always been a Cisco Systems differentiator, and the proposed system fits that market
position. The proposed P2MP system uses patented third-generation microwave technology to overcome the
classical microwave constraint that the transmitter and receiver must have a clear line of sight. The proposed
technology takes advantage of waves that bounce off buildings, water, and other objects to create multiple
paths from the transmitter to the receiver. The receivers are capable of making all these multipath signals
combine into one strong signal, rather than having them appear to be interference.
The capability to operate with high levels of multipath permits obstructed links to be deployed. This, in turn,
enables multicellular RF deployments and virtually limitless frequency reuse. Also, the antennae in the
system can be mounted on short towers or rooftops.
Although this is primarily a savings in the cost of installing a system, it has the added benefit of making the
installation less visible to the user's neighbors, which is very important in some regions.
The typical point-to-multipoint system for an SMB is shown in Figure: Hardware Components of the
Point-to-Point System (Only One of Four Possible Sectors Shown on HE Equipment).
The point-to-point system is similar, except that the customer premises equipment is another UBR7223 or
7246 router. The point-to-point system is shown in Figure: Hardware Components of the Point-to-Point
In both cases, integrating the wireless card directly into the router brings with it all the Cisco IOS features
and network management.
Figure: Hardware Components of the Point-to-Point System (Only One of Four Possible Sectors Shown on HE Equipment)
This open architecture permits many different vendors to participate, creating new products, features, and
services. Figure: Open Standard Wireless Architecture shows why many vendors will be interested in this
approach. By using a common IF, many different frequency bands can be utilized for many different
Other router and switch vendors will also be capable of entering the market because the IF-to-WAN
conversion is something that they can work into their product line. It also shows how Cisco will migrate the
IF into WAN interfaces in a range of existing and future router products.
Equally important, by making the wireless interface just one more WAN interface on a router, Cisco has
integrated all the network management for the wireless system into the normal router and switch network
management, such as CiscoView and CiscoWorks2000.
Figure: Hardware Components of the Point-to-Point System (Only One of Four Possible Sectors 21
Shown on HE
The system uses the next-generation microwave technology invented by Cisco Systems, called vector
orthogonal frequency-division multiplexing (VOFDM), to resolve the issue of multipath signals in a radiating
A transmitted signal will reflect off buildings, vegetation, bodies of water, and large, solid surfaces, causing
ghosts of the carrier (main or intentional) frequency to arrive at the receiver later than the carrier frequency.
Multipath signal issues are a liability for all radio systems except those without VOFDM or a feature to
cancel or filter the late-arriving signals.
Embedded in the OFDM-modulated carrier frequencies are training tones. These allow multipath-channel
compensation on a burst-by-burst basis. This is especially important on the uplink because each OFDM burst
may be transmitted by a different subscriber unit (SU) over a different multipath channel. The overall effect
of the VOFDM scheme is an RF system that is extremely resilient to multipath signals.
Raw channel over-the-air data rates are 36, 24, 18, 12, 9, and 6 Mbps. Excluding physical layer overhead, the
user rates are different for the downstream and upstream links. Downstream, these rates are 22.4, 17, 12.8,
10.1, 7.6, and 5.1 Mbps. Upstream, the rates are 19.3, 15.2, 11.4, 8.1, 6.2, 4.4, 4.2, 3.2, and 1.4 Mbps.
Various combinations of these rates are supported, depending on the cell type.
These are configuration parameters that can be set and changed. Thus, if a customer requests an increased
data rate service, the change can be made from the network operations center (NOC) without personnel
having to visit the customer site.
The service provider can make this as simple or as complicated as desired. Thus, one service city can have all
subscribers on a single data rate plan, while another city can offer time-of-day and day-of-week data rate
premium services.
Downstream and upstream user bandwidth can be assigned dynamically for session-based traffic or, during
initial registration for best-effort Internet data access, based on service flows for each user.
Duplexing Techniques
Time-division duplexing and frequency-division duplexing are the two common techniques used for
duplexing. There are challenges with each of the two approaches, related to implementation, flexibility,
sensitivity, network synchronization, latency, repeaters, asymmetrical traffic, AGC, and the number of SAW
filters, among others. After a study of the subject, it was decided that the TDD vs. FDD selection is not a
simple decision to make-indeed, the advantage marks are relatively close to one another. However, having
the benefit of the most recent information regarding the procurement of low-cost duplexors, development
priority was given to FDD scheme.
TDD is a duplexing technique that utilizes time sharing to transmit and receive data in both directions. Each
side is allotted a certain amount of time to transmit, generally in symmetric amounts. The TDD algorithms
are embedded into each of the RF processor boards and are synched by protocol instruction when the units
are first powered up. Commonly these synching protocols are updated on a routine basis.
In FDD, the total allocated spectrum of frequency is divided so that each end of the radio link can transmit in
parallel with the other side. FDD is commonly divided equally, but it is not symmetric on many links.
User bandwidth allocation is carried out by means of a Medium Access Control (MAC) protocol. This
protocol is based on the MAC portion of DOCSIS protocol developed by the Cable Labs consortium. The
MAC protocol assigns service flows (SID) to each user; depending on the quality of service (QoS)
requirements, the upstream MAC scheduler provides grants to fulfill the bandwidth needs. Similarly, the
downstream bandwidth is divided between active users of unicast and multicast services.
Each upstream channel is divided into intervals. Intervals are made up of one or more minislots. A minislot is
the smallest unit of granularity for upstream transmit opportunities.
For example, the request interval is used for CPE bandwidth requests and is typically multicast to all CPEs;
therefore, it is an interval open for contention. Multiple CPEs can attempt to send a bandwidth request; if the
request is granted, the base station will assign a series of minislots to the CPE in the next MAP message.
Contention is resolved via a truncated binary exponential back-off algorithm.
To support customer QoS requirements, six types of service flows are specified: Unsolicited Grant Service
(UGS), real-time Polling Service (rtPS), Unsolicited Grant Service with Activity Detection (UGS-AD),
non-real-time Polling Service (nrtPS), Best Effort (BE) Service, and a Committed Information Rate (CIR)
The intent of UGS is to reserve fixed-size data grants at periodic transmission opportunities for specific
real-time traffic flows. The MAC scheduler provides fixed-size data grants at periodic intervals to the service
flow. The QoS parameter for the given service flow sets the grant size, the nominal grant interval, and the
tolerant grant jitter.
The intent of the rtPS grants is to reserve upstream transmission for real-time traffic flows such as VoIP.
Such service flows receive periodic transmission opportunities regardless of network congestion, but they
release their transmission reservation when they are inactive. As such, the base station MAC scheduler sends
periodic polls to rtPS service flows using unicast request opportunities enabling subscriber wireless port to
request for the upstream bandwidth that it needs. The QoS parameter for such a service flow is nominal
polling interval and the jitter tolerance for the request/grant policy.
The intent of UGS-AD is to reserve upstream transmission opportunities for real-time traffic flows such as
VoIP with silence suppression. USG-AD is designed to emulate the capabilities of UGS service when active,
and rtPS service when inactive. The QoS parameter for such a service flow is nominal polling interval,
tolerated polling jitter, nominal grant interval, tolerated grant jitter, unsolicited grant size, and the
request/transmission policy.
The intent of nrtPS is to set aside upstream transmission opportunities for non-real-time traffic flows such as
FTP transfer. These service flows receive a portion of transmission opportunities during traffic congestion.
The base station MAC scheduler typically polls such service flows either in a periodic or a nonperiodic
fashion. The subscriber wireless port can use either the unicast request opportunities or contention request
opportunities to request upstream grants. The QoS parameter for such a service flow is nominal polling
interval, reserved minimum traffic rate, maximum allowed traffic rate, traffic priority, and
request/transmission policy.
The intent of the BE service is to provide an efficient way of transmission for best-effort traffic. As such, the
subscriber wireless port will use either contention or unicast request opportunities to request upstream grants.
The QoS parameter for such a service flow is reserved minimum traffic rate, maximum sustained traffic rate
and traffic priority.
CIR can be implemented in several different ways. As an example, it could be a BE service with a reserved
minimum traffic rate, or nrtPS with a reserved minimum traffic rate.
The frame and slot format is based on the MAC protocol. The downstream transmission is broadcast, similar
to Ethernet, with no association with framing or a minislot. The recipients of downstream packets perform
packet filtering based on the Layer 2 address-the Ethernet MAC or SID value. The upstream transmission is
based on a time-division multiple access (TDMA) scheme, and the unit of time is a minislot. The minislot
size varies based on upstream configuration settings and can carry data between 8 bytes and approximately
230 bytes. TDMA synchronization is done by time-stamp messages, and the time of transmission is
communicated to each subscriber by the MAP messages (a MAP message carries the schedule information
(map) for each minislot of the next data protocol data unit (PDU)). MAP messages are initiated by the MAC
scheduler in the base station and thus convey how each minislot is used (reserved for user traffic, for initial
invitation, or as contention slots). The contention slots are used for best-effort traffic to request bandwidth
from the scheduler. The frame time is programmable and can be optimized for a given network.
Accurately receiving an orthogonal frequency-division multiplexing (OFDM) burst requires burst timing and
frequency offset estimation. Burst timing means determining where in time the OFDM burst begins and ends.
Determining the difference between the local demodulating oscillator and the modulating oscillator at the
transmitter is called frequency synchronization, or frequency offset estimation.
Burst timing and frequency synchronization are required for the downstream link. The upstream link will be
frequency locked once the subscriber unit frequency locks the downstream signal. That is, the local oscillator
at the subscriber unit is synchronized to the base station oscillator by use of a frequency-locked loop. In this
way, the upstream transmission that arrives at the base station receiver will have nearly zero frequency offset.
As in any TDMA upstream, each subscriber unit must lock to the TDMA slot when transmitting on the
upstream. This is referred to as ranging each subscriber. As prescribed by the MAC layer, a subscriber fills
periodic ranging slots with a known sequence. This known sequence is used at the base station to determine
proper slot timing.
The upstream TDMA synchronization is done via time-stamp messages that carry the exact timing of the
base station clock. Each subscriber phase locks its local clock to the base station clock and then synchronizes
its minislot (unit of TDMA) counter to match that of the base station. Furthermore, ranging is performed as
part of initial acquisition to advance the transmission time of the subscriber so that the precise arrival of its
transmission is synchronized with the expected minislot time of the base station.
The average overall delay in the link depends on the particular bandwidth and spectral efficiency setting. In
all cases, the physical layer delay is limited to 5 ms in the downstream. The upstream physical layer delay is
less than 2 ms.
Power Control
Power control is done in real time to track rapidly changing environment. It is one facet of the system
capability to adjust on a packet-by-packet basis.
Receiver signal power at the subscriber is controlled through the use of an Automatic Gain Control (AGC)
system. The AGC system measures received power at the analog-to-digital converter (ADC) and adaptively
adjusts the analog attenuation. With AGC, channel gain variations on the order of 200 Hz can be
accommodated without impacting the OFDM signal processing.
Receive power at the base station is regulated through the use of an Automatic Level Control (ALC) system.
This system measures power levels of each subscriber and creates transmit attenuator adjustments at the
subscriber so that future communication is done with the correct transmit power level. This power control
loop is implemented in the physical layer hardware so as not to impact the MAC-layer performance.
Power measurements for the purposes of ALC occur on upstream traffic. Specific power bursts may be
requested by the base station MAC to power control subscribers.
Admission Control
A new user is admitted to the system by means of a software suite. Components of this suite are User
Registrar, Network Registrar, Modem Registrar, and Access Registrar.
Network Registrar supplies DHCP and DNS services for the CPEs and personal computers. Network
Registrar DHCP allocates IP addresses and configuration parameters to clients based on per-device policies,
which are obtained from an LDAP directory. Network Registrar allocates limited IP addresses and default
configuration parameters to inactivated devices, to steer users to the User Registrar activation page.
Modem Registrar adds TFTP and time services to Network Registrar for the CPEs. The Modem Registrar
TFTP builds DOCSIS configuration files for clients based on per-CPE policies, which are obtained from an
LDAP directory. Modem Registrar builds limited-privilege configuration files to inactivated CPEs.
Access Registrar supplies RADIUS services for the CPEs and the clients that are connected to the CPEs.
Access Registrar RADIUS returns configuration parameters to NAS clients based on per-subscriber policies,
which are obtained from an LDAP directory. Access Registrar returns limited-privilege NAS and PPP
parameters to unregistered subscribers and to inactivated CPEs.
As stated previously, the system employs frequency-division duplexing (FDD). Unlike time-division
multiplexing (TDD) systems, the equipment is not subject to cell radius limits. The only limitation to cell
radius is that imposed by free space attenuation (FSA) of the radio signals. Timing limitations imposed by
the MAC protocol on upstream and downstream channels would permit the cell radius to be beyond the radio
horizon (FSA notwithstanding).
Unless the subscriber density is very low, as in rural areas, very large cells are not recommended because
they may quickly become capacity-limited and are difficult to scale to meet the higher capacity demand.
Two architectures are described in this section. The first is a multicellular architecture, called the small-cell
pattern. The second architecture is known as a single-cell architecture. The baseline small-cell architecture
employs a 4 * 3 frequency reuse pattern. This means that a four-cell reuse pattern and three sectors are
employed within each cell or base station (BS). Within a cellularized network, a hexagonal cell is tiled out to
completely cover the service area. In our system, a four-cell tiling pattern is repeated over the service area.
This tiling pattern puts a lower limit on the reuse distance, thereby controlling interference levels. Employing
three sectors within each BS further reduces interference compared to omnidirectional antennae. A 4 * 3
reuse pattern works well for operations using obstructed (OBS) links. It uses a total of 24 channels: 12
channels downstream, plus 12 channels upstream.
Note that the number of MMDS channels used may be different than 12 + 12 because the system supports
channels narrower than 6 MHz. At any given BS, signals are received from subscriber units (SUs) over both
OBS links and line-of-sight (LOS) links. In general, OBS links are attenuated at 40 dB/decade; that is, R-4
path loss. LOS links, however, propagate based on R-2 path loss. Thus, if an SU has a LOS link to its BS, it
likely also has a LOS link to a reuse BS. To suppress cochannel interference from LOS links, horizontal and
vertical polarization are alternatively used on reuse cells. This results in an overall reuse scheme of 4 * 3 * 2
and (still) using a total of 24 channels. This reuse pattern can be continued to cover as large a geographical
area as desired. Improved frequency reuse can occur when networks are of more limited extent. This is
because there are fewer tiers of interfering cells. In these cases, greater C/I ratios are obtained, along with
greater network capacity (given a fixed amount of spectrum).
Admission Control 27
Our approach to frequency reuse for OBS links is conservative in that it does not rely on polarization
discrimination. Signals transmitted over multipath channels often experience depolarization. If a dual
polarization reuse scheme were employed, it may be very difficult to achieve 99.99 percent link availability
because as a reuse (undesired) channel is depolarized, it results in higher levels of interference to the
cochannel (desired) signal.
Within a cell, the upstream frequency band can be split into as many as four channels. The channel
bandwidths that can be configured are 1.5 MHz, 3 MHz, and 6 MHz. The downstream frequency consists of
one channel that again can be configured as one of 1.5, 3, or 6 MHz. The capability of the Cisco wireless
products to operate in these wide ranges of channel bandwidths allows the operator great flexibility in
designing the network for efficient usage.
A cell within the Cisco wireless access architecture consists of a downstream channel with up to four
upstream 1.5-MHz channels. By default, load balancing is performed on the upstream channels as CPEs enter
the network. Special algorithms run on CPE and the head end to ensure a uniformity of CPE loading on the
upstream channels. This allocation of CPEs across the upstream channels can also be done under user
Time-Slotted Upstream
Cisco's wireless access solution uses a MAC protocol based on DOCSIS. This protocol is based on a
broadcast downstream architecture and a time-slotted upstream architecture. The time slots for the upstream
govern the access rights of each CPE on to the upstream channel. There is a very sophisticated scheduler that
runs on the head end and allocates these time slots to all the CPEs. Resource sharing of the upstream
bandwidth is realized by each CPE making its request to send in a contention time slot, the head end
responding to it in a subsequent message downstream (called a MAP message), and the CPE using the
information in the MAP message to send the data in an appropriate time slot upstream.
Contention Resolution
The DOCSIS protocol uses the notion of contention time slots in the upstream. These time slots are used by
the CPEs to send a request to the head end for a time slot grant to send data. In a loaded upstream network, it
is possible for these contention slots to become very congested themselves and nonproductive. Cisco's
wireless head end uses an intelligent algorithm to ensure that the contention slots are evenly spaced,
especially in times of high upstream load. The CPEs also implement an intelligent algorithm that ensures that
the request grants from the CPEs are spaced evenly over all the contention slots in a given MAP message.
Traffic Policing
One of the most important features of the wireless access channel is its shared nature. At any given time,
several hundreds or thousands of CPE subscribers may be sharing an upstream or downstream channel.
Although this shared nature is useful for reducing the per-subscriber investment for the operator, two
important aspects must be considered while providing this access service:
The need to allocate this bandwidth fairly among all the users
The need to prevent misbehaving users from completely monopolizing the access
The Cisco solution uses sophisticated algorithms at the head end to police the traffic from each subscriber
Traffic Shaping
The traffic from each CPE can also be shaped by algorithms running at the head end. This allows the
operator to provision services to the CPE based on the critical nature of the traffic, customer needs, and so
on. The peak rates of traffic from each subscriber are measured on a continuous basis and are policed at
every request from the CPE. If the request from the CPE exceeds its allotted rate, the grant is delayed,
thereby effectively controlling the rate of data transfer from the CPE. Differentiated services can be offered
to subscribers. The operator can configure different maximum data rates for different wireless subscribers
and can charge accordingly. Subscribers requiring higher peak rates and willing to pay for the same can be
configured with a higher peak rate limit dynamically or statically.
We will use the generic reference model in Figure: Generic Reference Model for Broadband Wireless
Access. In this figure, reference points I-VIII refer to specific interfaces and/or functions. We describe each
of these interfaces or functions below.
Traffic Policing 29
Interface I: Wireless Subscriber Interface
Interface II: Subscriber Indoor Unit PHY/MAC Interface
Interface III: Subscriber Radio IF/RF Interface-This interface is a physical coaxial cable carrying IF,
digital control information, and DC powering for the ODU.
Interface IV: RF Air Interface-This interface is the over-the-air RF interface. It is in the MMDS
frequency band (2.500 to 2.690 GHz, and 2.150 to 2.162 GHz). The energy radiated from the
antenna is governed by FCC Rules and Regulations, Part 21.
The above descriptions of interfaces I to III represent Cisco Systems products by way of example. Such
products will interwork with the base station described next, via interface IV compatibility, but will have
many new and different CPE interfaces, features, and services.
Interface V: Base Station RF/IF Interface-This interface at the base station is a physical coaxial cable
carrying intermediate frequency (IF), digital control information, and DC powering for the outdoor
unit (ODU).
Interface VI: Base Station Indoor PHY/MAC Interface-This interface is internal to the Cisco router.
Interface VII: Network Connection Interface
The access wireless architecture consists of a base station system that serves a community of subscriber
systems. It is a point-to-multipoint architecture in the sense that the entire bandwidth on the upstream and
downstream is shared among all the subscribers. The protocol stack implemented to make all this work is
based on the DOCSIS standards developed by the Cable Labs consortium.
The current state of the art is the version by Cisco that includes a base station end (a UBR7200 router); the
subscriber end is in the 3600 or a 900 router series. The base station end and the subscriber end operate as
forwarding agents and also as end systems (hosts). As forwarding agents, these systems can also operate in
bridging or routing mode. The principal function of the wireless system is to transmit Internet Protocol (IP)
packets transparently between the base station and the subscriber location. Certain management functions
also ride on IP that include, for example, spectrum management functions and the software downloading.
Both the subscriber end and the base station end of the wireless link are IP hosts on a network and they fully
support standard IP and Logical Link Control (LLC) protocols, as defined by the IEEE 802 LAN/MAN
Standards Committee standards. The IP and Address Resolution Protocol (ARP) protocols are supported over
DIX and SNAP link layer framing. The minimum link layer minimum transmission unit (MTU) on transmit
from the base station is 64 bytes; there is no such limit for the subscriber end. IEEE 802.2 support for TEST
and XID messages is provided.
The primary function of the wireless system is to forward packets. As such, data forwarding through the base
station consists of transparent bridging or network layer forwarding such as routing and IP switching. Data
forwarding through the subscriber system is link layer transparent bridging as with Layer 3 routing based on
IP. Forwarding rules are similar to [ISO/IEC10038], with modifications as described in DOCSIS
specifications Section 188.8.131.52 and Section 188.8.131.52. Both the base station end and the subscriber end support
DOCSIS-modified spanning-tree protocols and include the capability to filter 802.1d bridge PDUs (BPDUs).
The DOCSIS specification also assumes that the subscriber units will not be connected in a configuration that
would create network loops.
Both the base station end and the subscriber end provide full support for Internet Group Management
Protocol (IGMP) multicasting.
Above the network layer, the subscribers or end users can use the transparent IP capability as a bearer for
higher-layer services. Use of these services will be transparent to the subscriber end and the base station end.
Link layer security is provided in accordance with DOCSIS baseline privacy specifications.
These capacities are based on 6-MHz downstream channels and 3-MHz upstream channels:
This high-capacity network has 83 cells in the network, each with 3 sectors. A total of 249 sectors are in the
network, each serving 21 SB and 510 HH. Overall, a total of 249 * 21, or 5,229, SBs are served by the
network; similarly, a total of 126,990 HHs are served.
The supercell (very large cell) network design is one that provides low coverage and low overall network
capacity. However, it may be attractive for initial network rollout because of the availability of existing (tall)
towers. In our supercell design, assuming that a sufficient number of MMDS channels are available, up to 18
sectors may be used. No frequency reuse is performed within the supercell, again because of sector-to-sector
isolation requirements that are greater than sector antennae can provide. Each sector operates independently.
Also, at least four MMDS-channels must be set aside as guard bands.
The number of sectors deployed on the supercell may be scaled as the demand for capacity grows. Because
there is no frequency reuse, no special requirements are placed on the design of the sector antennae. For
example, the same panel antenna used for a 3-sector supercell could also be used all the way up to 18 sectors.
However, to increase RF coverage, narrower-beam antennae may be employed to increase EIRP. This will be
effective as long as the supercell isn't capacity-limited (which is often the case).
The capacity of the supercell is given in Table: Network Capacity for Supercell. In this deployment model,
we have not differentiated between suburban and urban deployments. The assumption is that the desire is to
provide service primarily to subscribers in which LOS operation is possible. Because macrodiversity is not
possible in a supercell design, coverage becomes difficult. For example, the COST-231 Hata model predicts
an 80 percent coverage at a radius of only 15 miles-much smaller than the desired cell radius. Moreover, this
coverage is computed at the limits of the model's antenna heights-200 m for the HE, and 10 m for the SU
over suburban terrain.
If a lower availability objective were desired, the fade margin could be greatly reduced, thereby extending
the cell radius. More importantly, the sector-to-sector isolation would be greatly reduced, perhaps admitting
frequency reuse within the supercell. Because the cell is capacity-limited (there are many more subscribers in
the cell's radio footprint than there is capacity to service), this would be a tremendous benefit.
The multipath channel from both the front (desired) antenna and the rear (undesired) antenna must be the
same so that the fading from the desired and undesired antennae must be highly correlated.
The time rate-of-change of the multipath channel must be slow enough such that power control errors are
very small.
The following sections present both the general functions performed by the various configuration items or
building blocks segmented into transport and services products.
The transport layer is composed of the equipment that provides the transmission and reception of IF signals
between the rooftop and router equipment and the RF signals over the air. The transport equipment is
designed to work in an outdoor environment mounted on buildings or telecommunications towers. The P2MP
transport layer is physically segmented into hub and terminal equipment categories, as depicted in Figure:
Hub Site Equipment (Per Sector).
Rooftop Unit
The sole element of the P2MP transport layer at the terminal site is the RTU. The RTU is an integrated
antenna and RF transceiver unit that provides wireless transmission and reception capabilities in the 5.7 GHz
frequency region. Received and transmitted signals are frequency translated between the 5.7 GHz region and
an intermediate frequency (IF) in the 400 MHz range to the network interface unit (NIU).
The RTU mounts on the exterior of a subscriber's building. Some alignment is required to gain line of sight
(LOS) to the hub serving the RTU. Multiple RTUs can be deployed to provide path redundancy to alternate
hub sites. The RTU requires dual coax cable (RG-11) runs to the NIU for signal and power. The maximum
standard separation between the RTU and the NIU is 60 m. This separation can be extended via
application-specific designs.
Basic Receiver
A single basic receiver is required per 90 sector, if no return-path redundancy is required. The receive
module is an integrated 5.7-GHz receiver/down-converter/antenna. A collection of signals is received from
customer units operating in the 5.7 GHz band and is block down-converted to an intermediate frequency
signal. This signal is provided to any of the channel group types. Vertical or horizontal polarization is
High-Gain Receiver
A high-gain receiver is used in lieu of the basic receiver when higher link margin is required because of the
specific geographic conditions of deployment. The high-gain receive module is intended to be matched only
with the high-gain transmit module. The specifications are identical to those of the basic receive module,
except for physical package and antenna gain.
Because of the modularity of the SP2200 products, there is no one standard rack or set of racks. All SP2200
elements are designed to mount in a standard 19-inch (48.3-cm) open relay rack with a standard EIA hole
pattern or an equipment enclosure with 19 inches (48.3 cm) of horizontal equipment mounting space. Final
assembly of the equipment into racks is accomplished on site at initial install or over time as capacity
Environmental conditions such as rain and smog must be considered when deploying RF systems that
transmit at frequencies above 10 GHz because these conditions degrade the signal path and shorten the
maximum range for a given data link.
LMDS data links are generally about one-fourth that of MMDS or U-NIII links and require fairly strict
adherence to a line-of-sight implementation. One of the more favorable aspects of the LMDS frequency,
however, is that it has exceptional frequency reuse capabilities.
Data link availability is expressed in terms of the number of nines that follow the decimal point. For
example, 99.999 percent link availability means that a data link will be up and online (available) for all but
.001 percent of the year. Link availability is dependent on a wide range of items, but these generally begin
with fundamental RF system design issues such as antenna size, range between antennae, and atmospheric
conditions (for LMDS band).
The following should be noted in Table: A Brief Comparison of HomeRF, Bluetooth, and 802.11 WLAN
Basic Receiver 34
40- to 128-bit RC4 refers to very robust data security algorithms.
An 802.11 range of 1,000 feet refers to outdoor conditions. Indoor conditions are more difficult for
these types of RF systems.
802.11 power output of 1W is substantial.
The maximum number of devices supported depends on data rate per device.
The Aironet acquisition uses 802.11.
Although there are three standards in use in the United States, and an additional two are in use in Europe
(HyperLAN and HyperLAN2), the FCC thinks highly of the 802.11b standard, and a close relationship exists
between the FCC and the IEEE, which backs the standard.
At least 18 different types of wireless are in commercial use today. Therefore, as this technology becomes
more mainstream, users will need to be increasingly specific in their reference to the term. The different
types of wireless are quite unique to each other on numerous levels, and they require specific types of
expertise to deploy, use, and maintain.
In its state-of-the-art deployment, a wireless link emulates all the capabilities of a fully featured router, which
means that a wireless link can provide VPN, enterprise toll bypass, and MDU/MTU access services. This is
one of the primary differences between a Layer 2 product as provided by the majority of wireless vendors
and the Layer 3 solution provided by Cisco Systems.
Regardless of the provider of a wireless system, the fundamental elements remain relatively constant:
Data or network
Edge or access router
DSP medium
RF medium (coax, modulator/demodulator, antenna)
RF management software
Like every access medium or technology, wireless has its pros and cons. The pros include these:
Review Questions
Q - What is the primary difference between narrowband and broadband wireless?
A - WLAN enables the user mobility up to pedestrian speeds. Fixed wireless requires that both antennae
remain stable and fixed in their positions.
A - Data or network, edge or access router, DSP medium, RF medium (coax, modulator/demodulator,
A - Wireless is much less expensive to deploy than trenching for cabling; is much quicker to deploy because
a link can be up in a couple of hours; can go where cables can't, such as in mountainous or inaccessible
terrain; involves less red tape for deployment; and comes with an inherent high degree of security. In
addition, wireless provides broadband mobility-portability that tethered access doesn't provide.
Review Questions 36
Glossary Terms
The following list of terms was selected by their frequency of use when discussing Cisco wireless interests.
This list should not be considered comprehensive with respect to the wireless industry in general.
Furthermore, certain aspects of these acronyms remain in a state of flux and should be considered accurate
per the date of this document.
adjacent channel-A channel or frequency that is directly above or below a specific channel or
Glossary Terms 38
amplitude-The magnitude or strength of a varying waveform. Typically, this is represented as a
curve along the x-axis of a graph.
analog signal - The representation of information with a continuously variable physical quantity,
such as voltage. Because of this constant change of the wave shape as it passes a given point in time
or space, an analog signal may have a virtually indefinite number of states or values. This contrasts
with a digital signal, which is expressed as a square wave and therefore has a very limited number of
discrete states.
antenna - A device for transmitting or receiving a radio frequency (RF). Antennae are designed for
specific and relatively tightly defined frequencies, and are quite varied in design. An antenna for a
2.5 GHz (MMDS) system will not work for a 28 GHz (LMDS) design.
antenna gain - The measure of an antenna assembly performance relative to a theoretical antenna
called an isotropic radiator (radiator is another term for antenna). Certain antenna designs feature
higher performance relative to vectors or frequencies.
bandwidth - The frequency range necessary to convey a signal measured in units of hertz (Hz). For
example, voice signals typically require approximately 7 kHz of bandwidth, and data traffic typically
requires approximately 50 kHz of bandwidth.
BTA - Basic trading area; an area or footprint in which an entity is licensed to transmit its
frequencies. BTAs were established by Rand McNally and are defined as county lines. Rand
McNally licensed its mapping data to the FCC for ease of designation for site licenses.
broadband - In general, an RF system is deemed broadband if it has a constant data rate at or in
excess of 1.5Mbps. Its corresponding opposite is narrowband.
broadcast - In general, this is the opposite of narrowcast and infers that a signal is sent to many
points at the same time or is transmitted in an omnidirectional pattern.
CDMA - Code division multiple access; a transmission scheme that allows multiple users to share
the same RF range of frequencies. In effect, the system divides a small range of frequencies out of a
larger set and divides the data transmission among them. The transmitting device divides the data
among a preselected set of nonsequential frequencies. The receiver then collates the various data
pieces from the disparate frequencies into a coherent data stream. As part of the RF system setup, the
receiver components are advised of the scrambled order of the incoming frequencies. An important
aspect of this scheme is that the receiver system filters out any signal other than the ones specified
for a given transmission.
channel - A communications path wide enough to permit a single RF transmission.
coax cable - The type of cable used to connect Cisco equipment to antennae.
converter - RF systems have two fundamental frequencies: that which is sent over the air (carrier
frequency), and that which is sent back and forth between Cisco equipment and the antennae
(intermediate frequency). This is performed by a converter; also known as up or down converters or
transverters. The intermediate frequencies are split into a higher and lower frequency that is used for
either transmission or reception of data between the antenna assembly and Cisco devices.
dB - Decibel; a unit for measuring relative power ratios in terms of gain or loss. Units are expressed
in terms of the logarithm to base 10 of a ratio and typically are expressed in watts. dB is not an
absolute value-rather, it is the measure of power loss or gain between two devices. As an example, a
-3 dB loss indicates a 50 percent loss in power, a +3 dB reading is a doubling of power. The rule of
thumb to remember is that 10 dB indicates an increase (or loss) by a factor of 10. Likewise, 20 dB
indicates an increase (or loss) of a factor of 100, and 30 dB indicates an increase (or loss) by a factor
of 1000.
Because antennae and other RF devices/systems commonly have power gains or losses on the order
of magnitude of 4, dB is a more easily used expression.
dBi - dB referenced to an isotropic antenna (hence the "i") that is theoretically perfect in terms of
symmetric patterns of radiation. Real-world antennae do not perform with even nominal amounts of
symmetry, but this effect is generally used to the advantage of the system designer.
Glossary Terms 39
The FCC provides licenses to ensure maximum competition in a free market (although this is not
always obvious in the way the FCC manages the auctions) and spectral efficiency, which is another
way of stating efficient use of the RF spectrum.
LMDS - Local Multipoint Distribution Service; a relatively low-power license for broadcasting
voice, video, and data. Typically two licenses are granted in three frequencies each to separate
entities within a BTA. These licenses are known as Block A or Block B licenses. Block A licenses
operate from 27.5 to 28.35 GHz, 29.10 to 29.25 GHz, and 31.075 to 31.225 GHz, for a total of 1.159
MHz of bandwidth. Block B licenses operate from 31.00 to 31.075 GHz, and 31.225 to 31.300 GHz,
for a total of 150 MHz of bandwidth. LMDS systems have a typical maximum transmission range of
approximately 3 miles, as opposed to the transmission range of an MMDS system, which is typically
25 miles. This difference in range is primarily a function of physics and FCC-allocated output power
LOS - Line of sight; refers to the fact that there must be a clear, unobstructed path between
transmitters and receivers. This is essential for LMDS products and enhances general performance in
every RF deployment, compared to partial or completely obstructed data paths. The opposite of LOS
is non-line-of-sight (NLOS).
MMDS - Multichannel Multipoint Distribution Service; this is comprised of as many as 33 discrete
channels that are transmitted in a pseudorandom order between the transmitters and the receivers.
The FCC has allocated two bands of frequencies for each BTA-2.15 to 2.161 GHz, and 2.5 to 2.686
mobile wireless - Cisco does not provide mobile wireless components; instead, it provides backbone
devices such as a GGSN that support mobile wireless infrastructures.
Glossary Terms 40
NLOS - Non-line-of-sight; also known as obstructed path or pathway.
parabolic antenna - A dishlike antenna that sends RF waves in a highly focused manner. Such
antennae provide very large power gains and are highly efficient. This antenna is typical to Cisco's
LMDS, U-NII, and MMDS systems, but this is not the only design available or appropriate for those
path loss - The power loss that occurs when RF waves are transmitted through the air. This loss
occurs because the atmosphere provides a filtering effect to the signal. Certain electromagnetic
frequencies (very high and noncommercial) are completely blocked or filtered by the atmosphere.
point-to-multipoint - P2MP; generally infers the communication between a series of receivers and
transmitters to a central location. Cisco P2MP is typically set up in three segments to enable
frequency reuse. Cisco offers MMDS, U-NII, and LMDS systems in P2MP.
Point-to-point - P2P; has a higher bandwidth than P2MP because, among other things, it has less
overhead to manage the data paths and only one receiver exists per transmitter. Cisco offers MMDS,
U-NII, and LMDS systems in P2P.
RF - Radio frequency; generally refers to wireless communications with frequencies below 300
TDMA - Time-division multiple access; a technique for splitting transmissions into time slots, which
enables a greater number of users for a given frequency. A technique commonly used, as opposed to
U-NII - Unlicensed National Information Infrastructure. Cisco offers a wireless product for this in
the 5.7 GHz frequency. This frequency does not require the use or purchase of a site license, but, as
with all electronic devices sold commercially, it does require registration with the FCC.
The NII is a term coined by federal regulators to describe the access of information to citizens and
business. Equivalent to the term "information superhighway," it does not describe system
architecture or topology.
Wireless Access Protocol - A language used for writing web pages that uses far less overhead,
which makes it more preferable for wireless access to the Internet. WAP's corresponding OS is that
created by 3Com in its Palm Pilot. Nokia has recently adopted the Palm OS for its web-capable
cellular phone.
In this article, terms Base Station (BS), Head End (HE), and Hub are used interchangeably.
Glossary Terms 41


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Federal health officials are reporting a sharp increase in unprotected sex among gay American men over the past decade, a development that makes it harder to fight the AIDS epidemic.
Federal health officials are reporting a sharp increase in unprotected sex among gay American men over the past decade, a development that makes it harder to fight the AIDS epidemic.
The same trend recently has been documented among gay men in Canada, Britain, the Netherlands, France and Australia, heightening concerns among public-health officials worldwide.
According to the Centers for Disease Control and Prevention, the number of men who told federal health investigators that they had had unprotected anal sex in the last year rose nearly 20 percent from 2005 to 2011. In the 2011 survey, unprotected sex was more than twice as common among men who said they did not know whether they were infected with HIV.
Being tested even once for HIV is associated with men taking fewer risks, whether the test is positive or negative, health experts say. But the most recent survey found that a third of the men interviewed had not been tested in the past year.
The findings are worrying because �unprotected anal intercourse is in a league of its own as far as risk is concerned,� Dr. Thomas R. Frieden, director of the CDC, said yesterday as the figures were released.
The data, published in the agency�s �Morbidity and Mortality Weekly Report,� do not explain why unprotected sex has risen so rapidly, but a leading hypothesis, Frieden said, is that more men are � sero-sorting� � that is, those who are uninfected (�HIV seronegative� on lab reports) try to sleep only with other men who are uninfected � or who hope they are, or merely promise they are.
�The problem with sero-sorting is that it�s really easy to get it wrong,� Frieden said.
The CDC suggests that sexually active gay men get tested at least annually.
The number of new HIV infections in the United States has been stuck at roughly 50,000 a year for many years.


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WND Exclusive
'Socialist in Congress' proposes so-called Robin Hood Tax
Scheme could 'diminish importance of U.S. as a major financial market'
Rep. Peter DeFazio, D-Ore., who just proposed a so-called Robin Hood Tax on financial trades, is closely tied to the country's largest socialist organization.
DeFazio previously was listed on scrubbed sections of the website of the Democrat Socialists of America, or DSA, as being a member. He is a founder of the Congressional Progressive Caucus, which also was founded by and originally openly partnered with the DSA.
Earlier this week, DeFazio proposed the "Wall Street Trading and Speculators Tax Act," which some are calling the Robin Hood tax. The tax would impose a small fee on financial trades.
It evolved ideologically from a concept called the Tobin tax, which was originally defined as a tax on all spot conversions of one currency into another. That tax was hatched by Nobel Laureate economist James Tobin after the Bretton Woods system of monetary management ended in 1971.
Supporters claim DeFazio's bill could raise up to $35 billion annually.
The Congressional Budget Office, however, has warned that DeFazio's tax on certain financial transactions could "diminish the importance of the United States as a major financial market" and that "imposing the transaction tax would probably reduce output and employment."
The imposition of the Robin Hood Tax has been a key demand of the Occupy movement. It is heavily supported by billionaire George Soros.
Another prominent supporter of the Robin Hood Tax is Jeffrey Sachs, a Columbia University economist who crafted a controversial economic "shock therapy." Sachs is a key member of the Institute for New Economic Thinking, or INET.
Soros is INET's founding sponsor, with the billionaire having provided a reported $25 million over five years to support INET activities.
Last April, Sachs keynoted INET's annual meeting, which took place in the mountains of Bretton Woods, N.H.
The gathering took place at Mount Washington Hotel, famous for hosting the original Bretton Woods economic agreements drafted in 1944. That conference's goal was to rebuild a post-World War II international monetary system. The April gathering had a similarly stated goal – a global economic restructuring.
DeFazio, meanwhile, has been linked to the DSA, the principal U.S. branch of the Socialist International and one of the world's biggest and most influential socialist organizations.
Through the DSA, the Congressional Progressive Caucus, or CPC, was one of the programs of action the Socialist International realized in the early 1990s. The DSA helped to organize the members into the House Progressive Caucus, as the CPC was originally known.
The relationship between the DSA and CPC was evident on the DSA website, which previously listed Caucus founders as DSA members, including DeFazio.
The DSA-CPC files were subsequently removed from the Internet, although some remain accessible in the Internet archive.
After a list of alleged DSA members, including DeFazio, circulated on the Internet last year, long time DSA national director Frank Llewellyn claimed that not one member of Congress is a formal member of the DSA. He explained that in order to join, a person must fill out a form and pay dues.
Still, there is no masking the DSA's central role in founding the CPC. DeFazio previously even hosted the CPC in his offices.
Socialist founded, website hosted by socialists
The Congressional Progressive Caucus boasts more than 80 members.
In the January/February 1998 issue of Chicago DSA's "New Ground," Ron Baiman identified Sen. Bernie Sanders of Vermont and Rep. Barney Frank of Massachusetts as leaders of the Progressive Caucus in Congress which DSA "helped to organize."
Until November 2002, the website of the Progressive Caucus was hosted by the DSA. Following news reports that drew attention to the congressional website being hosted by the socialist organization, the list of CPC names was moved to the website of Sanders, I-Vt., an avowed socialist, and eventually to its own site.
The issue of the CPC being hosted on the DSA website rose again in June 2000 in connection with a heated dispute on the House floor between Defazio, Rep. Randy "Duke" Cunningham, R-Calif., and David R. Obey, Wis., over the "merits of the F-22 fighter plane."
When Cunningham stood to defend himself, he threw into his argument the fact the DSA website had a link to the CPC, which DeFazio then led.
Back in 2000, the relationship between the CPC and DSA was an open secret.
In an August 10, 2000, letter to the editor published in "The Kentucky Post," it was reported that then-Democratic Rep. Ken Lucas had received campaign funds from Reps. Marcy Kaptur, John Lewis, George Miller, Nancy Pelosi, and Charles Rangel, "among others on the far-left." The writer remarked that "those five names stand out because they are all members of the Congressional Progressive Caucus – a group closely aligned with the Democratic Socialists of America."
The CPC still had not moved to its own website on April 23, 2002. Balint Vazsonyi responded thusly in the "Washington Times" to the hypothetical question, "'What?" I hear you say. 'Socialists in the Congress of the United States?'"
Wrote Vazsony: "Dozens, dear reader, dozens. And they make no secret of it. Although of late it has been refurbished and the address altered, they have their own website. They call themselves members of the Progressive Caucus, until recently an arm of the Democratic Socialists of America, itself an arm of the Socialist International. The Progressive Caucus may be a separate entity now, but the details of its program, as advertised on the Web site, are indistinguishable from that of the Socialist International.
"To their credit, they make no secret of it. Only the rest of us prefer not to believe it."
In a follow-up article in November 2002, Vazsonyi dug deeper into the continued presence of the CPC on the DSA website. He discussed the issue of constitutionality and the ramifications of the relationship.
He wrote: "The Socialist International carries the torch for Karl Marx, Friedrich Engels, V.I. Lenin, Leon Trotsky, and Josef Stalin. Pay no attention to the desperate attempts by socialists to distance themselves from Stalin. For our purposes, it suffices to observe that every single tenet of the Socialist International is the exact opposite of the principles upon which America was founded, and which define the U.S. Constitution."
The CPC moved its website in late 2002.
'Socialists active in Congress"
In October 2009, the DSA newsletter reported that 70 congressional Democrats are active members.
The group also claimed 11 socialists sit on the House Judiciary Committee.
The DSA makes clear its preference for working within the Democratic Party for the change it seeks.
"Many socialists have seen the Democratic Party, since at least the New Deal, as the key political arena in which to consolidate this coalition, because the Democratic Party held the allegiance of our natural allies," the group states in the "Where we stand" section of its website.
"Through control of the government by the Democratic Party coalition, led by anti-corporate forces, a progressive program regulating the corporations, redistributing income, fostering economic growth and expanding social programs could be realized."
In addition to a national program of "massive redistribution of income from corporations and the wealthy to wage earners and the poor and the public sector," the DSA also calls for a breaking down the American-style notions of nationalism and national sovereignty.
"A program of global justice can unite opponents of transnational corporations across national boundaries around a common program to transform existing international institutions and invent new global organizations designed to ensure that wages, working conditions, environmental standards and social rights are 'leveled up' worldwide," the group says on its website. "The basis of cooperation for fighting the transnationals must be forged across borders from its inception. Economic nationalism and other forms of chauvinism will doom any expanded anti-corporate agenda."
It also states in the group's mission statement: "A democratic socialist politics for the 21st century must promote an international solidarity dedicated to raising living standards across the globe, rather than 'leveling down' in the name of maximizing profits and economic efficiency. Equality, solidarity, and democracy can only be achieved through international political and social cooperation aimed at ensuring that economic institutions benefit all people. Democratic socialists are dedicated to building truly international social movements – of unionists, environmentalists, feminists, and people of color – that together can elevate global justice over brutalizing global competition."
Communist anthem
While the DSA tries to paint distinctions between its brand of socialism and communism, before scrubbing its website, the site included a song list that included:
"The Internationale," the worldwide anthem of Communism and socialism.
"Red Revolution" sung to the tune of "Red Robin," with these lyrics: "When the Red Revolution brings its solution along, along, there'll be no more lootin' when we start shootin' that Wall Street throng. …"
"Are You Sleeping, Bourgeoisie?" Lyrics included: "Are you sleeping? Are you sleeping? Bourgeoisie, Bourgeoisie. And when the revolution comes, We'll kill you all with knives and guns, Bourgeoisie, Bourgeoisie."
The DSA is a political action committee and bills itself as the heir to the defunct Socialist Party of America. Its chief organizing objective is to work within the Democratic Party as the primary, but not sole, method of achieving public ownership of private property and the means of production.
"Stress our Democratic Party strategy and electoral work," explains an internal organizing document obtained by WND. "The Democratic Party is something the public understands, and association with it takes the edge off. Stressing our Democratic Party work will establish some distance from the radical subculture and help integrate you to the milieu of the young liberals."
Close working relationship
Demonstrating the close relationship between the DSA and the Progressive Caucus, in October 2010 WND reported the Democratic chairman of the powerful House Judiciary Committee was caught on tape meeting with DSA leaders to discuss how the group can cooperate to strengthen President Obama and advance their "one-world" plans.
Rep. John Conyers, D-Mich., who has a long history with the DSA, was recorded promoting a "one-world" government while asking the socialist group to organize against the war in Afghanistan and in support of Obama's policies.
Conyers was a special guest at a two-day convention in Detroit in March 1982 that resulted in the formation of DSA.
Conyers has spoken at numerous DSA events, including at the socialist group's national dinner in 2008, where he was the keynote.
Conyers was one of 13 founders of Congressional Black Caucus, which long has promoted far-left causes. He is the most prominent lawmaker lobbying to free Mumia Abu-Jamal, the convicted murderer of a Philadelphia police officer. He has advocated on behalf of the Marxist Nicaraguan Sandinista dictatorship and has called for the U.S. to end its sanctions against Fidel Castro's communist regime.
With additional research by Brenda J. Elliott


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Rebirth Brass Band
Top SongsSee All
Buckjump (feat. The Rebirth Brass Band, 5th Ward Weebie)Trombone Shorty 2011
Do Whatcha WannaUltimate Rebirth Brass Band 2001
Big Easy (feat. The Infamous Young Spodie & Rebirth Brass Band)Raphael Saadiq 2008
CassanovaUltimate Rebirth Brass Band 2004
(I Feel Like) Busting LooseUltimate Rebirth Brass Band 2004
Let's Go Get 'EmRebirth of New Orleans 2011
AlbumsSee All
Singles & EPsSee All
Live AlbumsSee All
CompilationsSee All
Appears OnSee All
MoviesSee All
About Rebirth Brass Band
As New Orleans music became more popular in the Northeast and festivals around the U.S. in the 1980s, two prominent brass bands from New Orleans took their music on the road: the Rebirth Brass Band and the Dirty Dozen Brass Band. The truth is, both groups have much to offer, as does a third group of Crescent City-based musicians, the New Birth Brass Band.
The Rebirth Brass Band was formed in 1983 by tuba player Phil Frazier and his brother, bass drummer Keith Frazier, and trumpeter Kermit Ruffins. Since the economics of keeping such a large group of musicians on the road in the '90s and into the new millennium was often a daunting task, there have been many personnel changes through the years. For example, Kermit Ruffins, now a prominent trumpeter and bandleader in his own right, worked with the Rebirth Brass Band throughout the '80s but left the group to start his own career in 1994. Similarly, trumpeter Shamarr Allen left the group to forge a solo career and has made a name for himself through theater gigs with Willie Nelson's band.
One significant break for the group came about when Allison Miner began managing them in the '80s. Through her network of contacts nationally, and internationally through her involvement with the New Orleans Jazz and Heritage Festival, she was able to secure the band bookings at prestigious festivals around the U.S. and Europe. The band's discography is long and varied but began with a very small label run by musicologist Chris Strachwitz, Arhoolie Records. In 1984, the band released its debut, Here to Stay, for Strachwitz's tiny label. By 1989, they landed at a then-growing roots music company, Rounder Records, to release Feel Like Funkin' It Up, and a slew of good recordings followed throughout the '90s. In 2008, they released 25th Anniversary, their 25th anniversary album, on their own label.
In the long run, it isn't the number or quality of albums Rebirth has released -- though their 2011 album, Rebirth of New Orleans, released in April 2011, did well on the jazz radio charts, which is due to the great cross-section of fans the band has attracted over the years. Founder Phil Frazier has said he's proud of the diverse crowds the band regularly attracts at shows in New Orleans or anywhere else in the U.S., Canada, and Europe. A wide spectrum of ages and ethnic groups finds something comfortable and something they can relate to in the meld of classic R&B, New Orleans funk, soul, rock, and jazz the band performs. Move Your Body was released in 2014. ~ Richard Skelly
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Together We Are Stronger
Save Our Salmon has merged with the Watershed Watch Salmon Society
Effective on January 1st, 2015, the SOS Marine Conservation Foundation (SOS/Save Our Salmon) has merged with the Watershed Watch Salmon Society (WWSS/Watershed Watch) in order to focus resources and be an even stronger force in reducing the impacts of overfishing, habitat destruction, unsustainable aquaculture, irresponsible hydro development, and government indifference, on BC's wild salmon and the marine environment.
For further information on the merger and examples of past collaboration between SOS and WWSS, please see below.
To continue on the team working for the good of BC's wild salmon and continue receiving email updates, please click here.
To make a donation to help BC's wild salmon and all that depends on them please click here.
For information on the KUTERRA land-based closed containment salmon farm, please see www.kuterra.com.
For information on land-based closed containment aquaculture in general please see Watershed Watch's Closed Containment page.
Details on the merger of SOS and WWSS
Current SOS initiatives focused on sustainable aquaculture will now operate through WWSS. Eric Hobson, past president of SOS, will join the Board of Watershed Watch. Eric will also continue as Vice-Chair of the Board for KUTERRA. Effective January 1, 2015, Dr. Craig Orr will retire as Executive Director of WWSS, passing the role of Executive Director to Aaron Hill. Dr. Orr will continue to be actively engaged as a Conservation Advisor on key issues such as salmon aquaculture and local projects in Coquitlam. Members of the SOS Solutions Advisory Committee (SAC), will continue with Watershed Watch, investing their efforts and expertise into the many issues facing BC's Wild Salmon upon which so much depends. Dr. Craig Orr will also join the SAC. Jackie Hildering, past Communications Director for SOS will be focussing her efforts on marine education and whale research through "The Marine Detective" and the Marine Education and Research Society. For further information on the merger or other details, please contact WWSS Operations Director, Trish Hall at firstname.lastname@example.com.
Examples of Recent Collaboration Between WWSS and SOS
Environmental petitions to the Auditor General of Canada regarding the Cohen Inquiry into the Decline of Sockeye in the Fraser River.
Public awareness:
- Relaying opportunities for comment regarding proposed regulatory changes and expansion applications.
- Maintaining the Cohen Report Card which tracks deadlines and (in)action on the Cohen Commission's Final Recommendations.
- Tracking open net-pen Atlantic salmon farm expansion applications and providing on line summaries
- Media releases and letters to the editor on issues related to protecting wild salmon and the marine environment.
- Bulletins on important events e.g. the 2nd anniversary of the Cohen Final Report Recommendations.
Regulatory (working together with the Pacific Salmon Foundation and the David Suzuki Foundation as the Conservation Regulatory Working Group):
- Inputting collectively on concerns about open-net Atlantic salmon farm expansion applications e.g. Hope Island.
- Attempting to achieve greater transparency and input of independent science into the Aquaculture Management Advisory Committee (AMAC) process.
- Commenting on DFO's review of marine finfish aquaculture siting criteria
- Commenting on the proposed Aquaculture Activities Regulations which would allow the dumping of waste, pesticides and drugs into the marine environment