Data Infrastructure

Mobile data uses much of the same infrastructure as voice, with a structure similar to BTSs and BSCs. However, instead of telephone-style switches, it needs Internet-style routers, which send data in small packets rather than through a continuous circuit. Most voice operators are now upgrading their systems to handle packet data, with the most common upgrade being GPRS. As explained in Chapter 4, "PCS Standards" , this was designed for GSM and can easily be adapted for all TDMA networks. CDMA already has some packet facilities built in, but is still used by data networks.

Mobile operators are rushing to deploy GPRS because it will enable them to use their capacity more efficiently; data effectively rides free during gaps in voice conversation and when the network is not busy, though congestion will occur at peak time. It is also relatively cheap, with standards existing to keep the cost down. According to wireless vendor Nokia, a very basic GPRS upgrade can cost only $1 million, compared to the $8 billion that Vodafone Airtouch paid for a third-generation licence UK license. Such a basic upgrade would provide limited services, but the cost for a more comprehensive network is still measured only in tens of millions.