81 Allocation of goodwill to Cash Generating Units  4. Business combination continued  The carrying amount of goodwill is allocated to the two CGUs (strategic business units) as follows:  [1] No allocation was done in 2011 as the initial accounting for the business combination was incomplete by the end of reporting period. The end of the measurement period was in 2012, where  reliable information about the facts and circumstances existed as of acquisition date was available.  As described in note 2 in more detail an impairment loss must be recognized if the carrying amount of a cash generating unit exceeds its recoverable  amount. The recoverable amount can either be measured as the fair value less cost to sell or the value in use. In Q4-2012 the company performed a  separate impairment test for the two relevant CGU’s based on the value in use to determine the recoverable amount. The calculation of value in use for both connectivity and mobile systems units is most sensitive to the following assumptions:  Return on sales – Return on sales is calculated by dividing the EBITDA by net sales. The EBITDA is defined as the operating profit (loss) excluding  depreciation and amortisation expenses as reported in note 24.  Discount rates – Discount rates represent the current market assessment of the risks specific to each CGU, taking into consideration the time value of  money and individual risks of the underlying assets that have not been incorporated in the cash flow estimates. The discount rate calculation is based on  the specific circumstances of the Group and its operating segments and is derived from its weighted average cost of capital (WACC). The WACC takes  into account both debt and equity. The applied WACC represents a post-tax discounting rate. The cost of equity is derived from the expected return on  investment by the Group’s investors. The cost of debt is based on the interest bearing borrowings the Group is obliged to service. Segment-specific risk is  incorporated by applying individual beta factors. The beta factors are evaluated annually based on publicly available market data. The calculation of the  recoverable amount is based on post-tax cash flows discounted using a post-tax discount rate. The result would have been the same, had pre-tax cash  flows been discounted using a pre-tax discount rate.  Growth rate estimates – Rates are based on company’s industry research and applied for calculation of perpetuity. The discounted cash flow calculations use projections that are based on management’s expectations covering the assessment year 2013. The planning  horizon reflects the assumptions for short-to mid-term market developments. Cash flows for the assessment years 2014 and 2015 are extrapolated  using appropriate growth rates. Key assumptions on which management has based its determination of the value in use include the development of key  assumptions mentioned above. Cash flow calculations are supported by external sources of information.  Goodwill impairment testing  Key assumptions used in value in use calculations   Return on sales;   Discount rates;   Growth rates used to extrapolate cash flows beyond the planning period.  Mobile Systems  Connectivity  2012 US$000 2011  1) US$000  2012 US$000 2011  1) US$000 Goodwill  5,150 n/a  27,133 n/a We expect additional value from the acquisition in respect of entry to new markets, internationalisation, cross-selling opportunities and customer  diversification. Besides for the connectivity segment we also expect additional value from the acquisition for our Mobile Systems segment. The synergies and other effects described above were measured on the basis of the Group’s current planning; the planning horizon was three years  including one budgeted year and two additional forecasted years. The assumptions were the same that we applied for the goodwill impairment test as  described below.