src/Message.php
protected function encodeMessage($message)
    {
        $replaceCharacters = array(
            'Δ' => '0xD0',
            'Φ' => '0xDE',
            'Γ' => '0xAC',
            'Λ' => '0xC2',
            'Ω' => '0xDB',
            'Π' => '0xBA',
            'Ψ' => '0xDD',
            'Σ' => '0xCA',
            'Θ' => '0xD4',
            'Ξ' => '0xB1',
            '¡' => '0xA1',
            '£' => '0xA3',
            '¤' => '0xA4',
            '¥' => '0xA5',
            '§' => '0xA7',
            '¿' => '0xBF',
            'Ä' => '0xC4',
            'Å' => '0xC5',
            'Æ' => '0xC6',
            'Ç' => '0xC7',
            'É' => '0xC9',
            'Ñ' => '0xD1',
            'Ö' => '0xD6',
            'Ø' => '0xD8',
            'Ü' => '0xDC',
            'ß' => '0xDF',
            'à' => '0xE0',
            'ä' => '0xE4',
            'å' => '0xE5',
            'æ' => '0xE6',
            'è' => '0xE8',
            'é' => '0xE9',
            'ì' => '0xEC',
            'ñ' => '0xF1',
            'ò' => '0xF2',
            'ö' => '0xF6',
            'ø' => '0xF8',
            'ù' => '0xF9',
            'ü' => '0xFC',
        );

        $message = utf8_decode($message);
        $message = str_replace('"', '\"', $message);
        $message = strtr($message, $replaceCharacters);

        return $message;
    }
protected function encodeMessage($message)
    {
        $replaceCharacters = array(
            'Δ' => '0xD0',
            'Φ' => '0xDE',
            'Γ' => '0xAC',
            'Λ' => '0xC2',
            'Ω' => '0xDB',
            'Π' => '0xBA',
            'Ψ' => '0xDD',
            'Σ' => '0xCA',
            'Θ' => '0xD4',
            'Ξ' => '0xB1',
            '¡' => '0xA1',
            '£' => '0xA3',
            '¤' => '0xA4',
            '¥' => '0xA5',
            '§' => '0xA7',
            '¿' => '0xBF',
            'Ä' => '0xC4',
            'Å' => '0xC5',
            'Æ' => '0xC6',
            'Ç' => '0xC7',
            'É' => '0xC9',
            'Ñ' => '0xD1',
            'Ö' => '0xD6',
            'Ø' => '0xD8',
            'Ü' => '0xDC',
            'ß' => '0xDF',
            'à' => '0xE0',
            'ä' => '0xE4',
            'å' => '0xE5',
            'æ' => '0xE6',
            'è' => '0xE8',
            'é' => '0xE9',
            'ì' => '0xEC',
            'ñ' => '0xF1',
            'ò' => '0xF2',
            'ö' => '0xF6',
            'ø' => '0xF8',
            'ù' => '0xF9',
            'ü' => '0xFC',
        );

        $message = utf8_decode($message);
        $message = str_replace('"', '\"', $message);
        $message = strtr($message, $replaceCharacters);

        return $message;
    }
Encode a message to the retarded GSM-charset.

@param  string $message

@return string