Ericsson wants edge with enhanced GSM

Ericsson wants edge with enhanced GSM
Steve Bush Ericsson has demonstrated wireless multimedia services at 384kbit/s using its EDGE (enhanced data rates for GSM evolution) technology. “EDGE is compatible with non-enhanced GSM,” said Jonas N?slund, product manager at the company’s GSM division. “We use a different modulation technique which increases the basic data rate in the channels from 9.6kbit/s to 48kbit/s.” Ericsson has moved from GSM’s GMSK (Gaussian filtered minimum shift keying) to 8PSK, which uses eight phase shifts to encode the signal. “GMSK was originally chosen to give good coverage with voice signals and an easy-to-make power amplifier,” said N?slund. “8PSK gives the increased data rate, up to 70kbit/s eventually, when you are close to the basestation. Communication is not lost as you move away. It decreases gradually, eventually to a normal GSM channel speed.” The 384kbit/s is achieved by combining eight time slots. Unlike UMTS, which is the incompatible high speed wireless system proposed to replace GSM in the next century, installing EDGE is claimed to be straight forward. “You just pull out the standard transceiver card in the basestation and replace it with an EDGE version,” said N?slund. Ericsson sees EDGE as a technology for high traffic areas. “It is the sort of service that would be installed in the City of London or at Heathrow airport,” said N?slund. “We are developing a small indoor basestation specifically for places like airports.” Two classes of hand terminal are envisaged. One that only receives high data rates and one that transmits as well. The two-way version is expected to carry a small, ten to 20 per cent, bulk penalty. “It will need a new power amp and be more complex, but not as difficult as dual mode,” said N?slund.


Leave a Reply

Your email address will not be published. Required fields are marked *

*