GPRS links to 3G

DUBLIN, Ireland-General Packet Radio Service (GPRS) has been dogged by delays and technical problems ever since it emerged as the mobile industry’s bridge between GSM and third-generation (3G) technology. But the modest development of other so-called 2.5G platforms should ensure that GPRS becomes more than a mere stepping stone to next-generation mobile services.

Sara Harris, Strategy Analytics European senior industry analyst, reckons that many of the problems faced by GPRS can be traced to misunderstanding between researchers and telecommunications executives. “Research and development managers started talking about theoretical speeds of up to 2 Mbps and when the marketing executives heard this they started talking about very high-speed services as if they were just around the corner. The word “theoretical” got lost in the translation and everyone got very excited about steaming video over mobile and other services.”

However, Dean Sirakides, director of GPRS product management at Motorola, claims that 2 Mbps was always a 3G target. “I don’t think anyone ever promised GPRS at these speeds. Speeds of 144 kbps or even 177 kbps were discussed but those rates assumed the highest data rate using all eight time slots.” Enda Hardiman of Hardiman Telecommunications explained that since GPRS works by allocating multiple time slots to single users, with current spectrum allocations there is an inverse relationship between speeds achievable by users and numbers of users that can be concurrently supported by base stations. Even Motorola’s Sirakides admits that speed was the wrong aspect for the industry to focus on. Most observers now believe that GPRS will deliver a maximum of 128 kbps under ideal conditions.

Yet despite all these problems GPRS has strengthened its position relative to other post-GSM technologies. The obvious alternative is high-speed circuit switched data (HSCSD). However, this has developed into a niche corporate application most suited to file transfer and videoconferencing where the user requires fixed bandwidth. Because it is circuit-based rather than packet-based, it makes less efficient use of bandwidth. Enhanced Data for Global Evolution (EDGE) was initially promoted as the step between GPRS and 3G, but it seems to have fallen out of favor completely. In any case, the 384 kbps maximum data rate ascribed to EDGE is at the top end of medium-term expectations for 3G.

Fears that 3G would quickly supersede GPRS are also likely to prove unfounded. If early industry forecasts had proved accurate, third-generation services would now be widely available across Europe, but this has not happened and wide-scale 3G implementation is unlikely before at least 2003.

According to Sirakides, GPRS is crucial to the success of 3G. “Operators must be successful with GPRS if they are to have any chance recovering 3G investments. Marketing, billing and service management must all be worked out to support the wireless data market and GPRS is the ideal place to start since the investment in infrastructure is very low because new base stations are not required.”

“GPRS was overstated in the nirvana of dot-com-induced euphoria,” added Hardiman. “It will indeed act as a precursor to 3G. Our view is that GPRS will coexist with 3G for some time (perhaps four years) with services and users migrated as 3G rollout achieves ubiquity.”

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