18.7 2.5G: Half-Step Forward to Wireless Broadband


18.7 2.5G: Half-Step Forward to Wireless Broadband

The switch from the circuit-switched networks to packet-switched networks provoked the carriers to heavily invest in another new generation technology: 2.5G. Based on the digital transmission protocols, the 2.5G is not a single wireless standard, but a collection of several. Bolting on to existing 2G infrastructure built on the operational GSM, CDMA, TDMA, and PHS standards among others, 2.5G CPRS and CDMA2000 standards are expected to provide faster data speeds up to 171 kbps. However, among the most-important attributes that 2.5G wireless Internet technologies can offer is wide area coverage. GSM/GPRS is already available in most of the United States and is widely available throughout Asia and Europe. AT&T expected the national rollout of GSM/GPRS to be completed by the end of 2002. If all goes as planned, in the near future mobile phone users will be able to dial from their phones anywhere they travel without worrying about coverage areas. Wireless carriers are putting major roaming agreements in place that will break down the regional use barriers. GSM and GPRS are fairly easy and affordable for the wireless carriers to deploy, and almost become necessary for their survival. After all, maximum throughput will not matter if users cannot access the network. Carriers are expected to spend some $2 billion over the next several years, with about 95 percent of this spending earmarked for GPRS.

Although GPRS and CDMA2000 definitely offer higher speeds, they still do not provide the true broadband that mobile end users and mobile content providers expect. While specifications suggest data rates of 144 kbps for CDMA2000 and 171 kbps for GPRS, these speeds are theoretical maximums. The important thing to keep in mind is that the maximum 171 kbps throughput is for an entire channel, and each channel has to support multiple callers, and within each channel there are multiple frames, and within each frame there are eight time slots. So, in reality users usually hit the maximum throughput of 33 kbps. Yet, 2.5G has already created success stories in the mobile Internet services area. In August 2002, Audiovox launched Thera in concert with Verizon Wireless — the first American Pocket PC with a built-in phone. Thera was the first PDA with the built-in connectivity to one of the fastest next-generation wireless networks in the United States, offered by Verizon Wireless. The Verizon Wireless Express Network, using the first phase of the CDMA2000 technology was designed to provide effective data rates of 40 to 60 kbps. With Thera, users can make phone calls, access e-mail and the Internet or network data, as well as use mobile services applications on demand.

For the most part, at the time of this writing, the 2.5G standards are looked upon as an intermediary step on the way to the true fast-speed wireless Internet access promised by 3G technologies. Yet, there are many positives that carriers and wireless Internet service providers can capitalize on. Some believe that in its glory, 2.5G may prove to be enough for the consumer, given that the right application will be offered. For consumers, technological advancement is not the main driver for adoption. Instead, viable applications and ease-of-use are two main prerequisites for mass-market acceptance. 2.5G does offer many features to the end user that make it more usable. With Instant IP access or "always-on" service offered by GPRS, users no longer need to dial up every time they connect to the wireless data network. They can be instantly notified of new messages or information according to their own preset preferences. In addition, the "always-on" feature can be used to add location/proximity and personalization services to customers. Moreover, based on the packet-switched versus circuit-switched data technologies, with 2.5G users will pay for data volume instead of air time, offering better value. Finally, unlike other earlier technologies, Metricom's Ricochet being a good example, 2.5G rollout is timed well with other supporting technologies, such as location services through GPS and network-based location; biometrics offering personalization; miniaturization allowing integration of more memory, energy, and processing power in portable devices; voice recognition offering easy access and interface; Bluetooth; Wi-Fi; and others. Many see 2.5G as a great market experiment powerful enough to open new business models, new entrants, and a whole slew of new business and consumer products and services.




Wireless Internet Handbook. Technologies, Standards and Applications
Wireless Internet Handbook: Technologies, Standards, and Applications (Internet and Communications)
ISBN: 0849315026
EAN: 2147483647
Year: 2003
Pages: 239

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net