Here is an article on wireless data from tele.com (long):
telecom99news.itu.int
On the Road to CDMA
But how smooth will the path be for cdmaOne as a unified standard draws nearer?
Tammy Parker, Contributing Writer
Much as all roads once ostensibly led to Rome, a plenitude of next-generation wireless paths are heading to interface technologies based on code-division multiple access (CDMA). Yet today's operators that are already using a form of narrowband CDMA, branded cdmaOne, face intriguing twists and turns as they evolve toward third-generation technology that will offer high-speed data and multimedia options.
The face of 3G is changing now that supporters of wideband CDMA, primarily based in the global system for mobile communication (GSM) camp, and supporters of cdmaOne have agreed to work together. However, this new commitment to cooperate on a unified CDMA standard for 3G wireless--cemented in May when L.M. Ericsson AB (Stockholm) bought the terrestrial CDMA infrastructure business of erstwhile rival Qualcomm Inc. (San Diego, Calif.)--has not significantly changed the migration trail for current cdmaOne operators who want to offer high-speed data services.
Creation of a unified, global CDMA standard with multiple access technologies will certainly affect the final design of cdmaOne's 3G solution, called cdma2000. Nonetheless, the groundwork has already been laid for a sequence of upgrades that are unique to second-generation cdmaOne networks.
While the wireless data market has been less than scintillating--most wireless operators report that fewer than 3 percent of their subscribers use data services--familiarity with the Internet and a new generation of data-savvy users is expected to drive future growth. Allied Business Intelligence Inc. (ABI, Oyster Bay, N.Y.) predicts a global market of 25 million mobile data subscribers by the end of 2000 and 89 million by the end of 2007. Another study from Forward Concepts Co. (Tempe, Ariz.) forecasts the worldwide 3G terminal market will total US$1.5 billion in 2001 and grow to $9.2 billion in 2005. Those types of figures are driving cdmaOne operators to start experimenting with data initiatives now.
Product Variations
The cdmaOne infrastructure vendors, as well as operators, are wrestling with a variety of standardized data initiatives and vendor-specific data enhancements. Many vendors' current infrastructure is capable of basic circuit-switched data at 14.4 kbit/s based on a standard called IS-95A, and some are stepping into low-speed packet-switched data. Analog faxing is also possible, thanks to an enhancement called IS-707A.
But carriers are being cautious about forays into data. Mexican operator Pegaso PCS (Mexico City) plans to offer at least rudimentary packet data services over its network. But Victor O'Farril, senior manager of business development, says data users require special vertically integrated solutions. "Therefore we expect to establish relationships that will provide the specific solutions through third-party vendors," he says.
He adds that while Pegaso is starting out as a mobile services provider, the operator has its eye on wireless local loop (WLL) markets, which could entail more data enhancements. "It is highly probable that customers on our WLL will ask for the benefits of high-speed packet data," he says.
South Korean operators have been especially aggressive on data. For instance, LG TeleCom Ltd. (Seoul) has offered circuit-switched data since February 1998 and packet mode since late 1998. Yet many U.S. operators have been content to offer voice-only services with limited one-way Short Message Service (SMS), although they are beginning to consider offering at least circuit-switched data.
The more aggressive data supporters in the cdmaOne community are gearing up for a standards-based advance in data capabilities: the IS-95B standard, which allows for high-speed packet-switched data at 115 kbit/s and a sustained bit rate of 64 kbit/s. Operators with the oldest cdmaOne equipment will likely need to make base-station hardware and software changes to accommodate the new standard, but those with fairly new networks might only need software upgrades. "If you support the maximum data rate in both the forward link and the reverse link, then that would have a hardware impact. But there is also a suggestion that if you implement it in an asynchronous manner, then the upgrade should mainly be software," says Yiuman Leung, senior manager of CDMA product line management for Canadian vendor Nortel Networks Corp.
IS-95B technology combines channels to provide for faster data speeds. But IS-95B's data strength is also its primary weakness: By joining multiple channels for data, it may reduce the channels allocated for voice. "If you run data at high speed [using IS-95B] and are sending more bits and bytes over the air vs. a voice call, that implies that you will use up more capacity," says Leung. For that reason, many operators are shying away from this advance.
Asia is the first to welcome IS-95B, perhaps due to a service provider affinity for having the latest and greatest. Youn-Kwan Kim, vice president with LG TeleCom, says his company, as well as other Korean wireless operators, are implementing the standard even though a 64-kbit/s connection using IS-95B could eat up as much as one-third of channel capacity.
“We don't have many data customers, and there's no real revenue from that type of service. But we will offer it to get a competitive edge,” he says. Kim also feels that the same reasoning is driving Japanese cdmaOne carriers IDO Corp. (Tokyo) and DDI Cellular Group (Osaka) to offer IS-95B. He adds that operators in Korea and Japan cannot risk waiting for another solution-1XRTT-which most consider a more advantageous technology.
Heralding Capacity Gains
Conceived as an early evolutionary step on the ladder to 3G, 1XRTT is the initial phase of the cdmaOne community's proposal for 3G wireless service. The standard, sometimes referred to as IS-95C, promises real data speeds of 144 kbit/s and a sustained bit rate of 307 kbit/s. Even though it uses the regular cdmaOne 1.25-MHz carrier, 1XRTT will likely require hardware and software changes for the switch and base stations. Unlike the potential capacity reductions inherent in IS-95B, however, 1XRTT is expected to double the airlink capacity, the number of available Walsh codes and the battery life of the handset.
Among operators planning to test 1XRTT by early 2000 are Korea's LG TeleCom, Sprint PCS (Kansas City, Mo.) and Bell Atlantic Mobile (BAM, Bedminster, N.J.) in the United States, and Australia's Telstra Corp. Ltd. (Sydney), which is slated to commercially launch its 800-MHz cdmaOne network in October 1999.
Telstra's 1XRTT tests are slated for early 2000.The operator is hoping data services and ready Internet access will make its digital offering attractive to the company's 1.3 million analog subscribers, two-thirds of whom will be regulated off its analog network by the end of 1999.
Telstra also operates a 900-MHz/1800-MHz GSM network in Australia with more than 2.5 million subscribers. According to Greg Young, Telstra's senior product manager for CDMA, the operator is conducting internal tests of services based on the Wireless Application Protocol (WAP) and is planning high-speed data tests on its GSM platform. But the company is reserving judgment about commercial introductions of high-speed data on either its GSM or cdmaOne networks until trial results are in.
"We want to find a cost-effective way for delivering high-speed data to users," says Young. The company, he says, needs to uncover the most prudent way to implement such service into its infrastructure and maintain low operating costs per bit or minute. The company also will examine billing models for data, commercial viability of data services and likely data applications.
Young admits to skepticism regarding the short-term viability of data services, given that Telstra's 9.6-kbit/s GSM data service has not generated significant growth. Like many, though, he feels data will eventually be a wireless revenue generator once the right applications, devices, services and pricing come together.
Other Possibilities
Questions about wireless data's take-up potential have led vendors and operators to consider other alternatives for implementing cost-effective data services. For instance, Qualcomm developed its High Data Rate, or HDR, solution as a new architecture for wireless systems that need an interim solution on their way to 3G.
HDR requires the use of a separate 1.25-MHz carrier from that used for voice traffic in order to provide a peak data rate of 1.8 Mbit/s. The technology also enables a direct connection to the Internet or another packet network without routing through a base-station controller. Given that, an operator might choose to implement 1XRTT for its higher voice capacity but add HDR capability as its data solution, says Gwenn Larsson, director of technical marketing for Qualcomm's infrastructure division, which is being bought out by Ericsson.
Qualcomm will offer HDR to other vendors, including Ericsson, for commercialization. American operator US West Wireless LLC (Denver) was the first company to sign up for HDR trials, examining the technology's suitability for high-speed, fixed-access applications.
In The End
Of course, the ultimate destination in the cdmaOne data migration is true 3G wireless packet data services at 1 to 2 Mbit/s within 5 MHz of bandwidth. The technological solution for this is termed cdma2000 Phase II, or 3XRTT, because it offers three times cdmaOne's usual 1.25 MHz channel configuration. Some suggest that operators might skip all of cdmaOne's other data iterations in order to wait for 3XRTT availability, particularly if it fits comfortably into a broader family of wideband CDMA solutions.
Moving from 1X to 3X will entail significant hardware changes on the RF front end to accommodate the transition from 1.25 MHz to the 3G bandwidth of 5 MHz, Nortel's Leung says. However, the minute details of 3XRTT technology still need to be ironed out before the end of 1999, particularly in light of work being done on creating a single CDMA standard for 3G with multiple access modes.
"That's going to involve a fairly high degree of coordination between standards bodies under the guidance of the ITU," says William Bold, Qualcomm's vice president of government affairs. Recalling the separate work done on W-CDMA and cdma2000, Bold says, "we had two processes going on parallel tracks." But now the tracks are moving much closer together, he says, requiring close cooperation from those driving 3G development.
Work on a common CDMA standard, even with a set of different access methods, holds the promise of global roaming with multimode/multiband handsets and some economies of scale both in infrastructure and handsets. And while some question the commercial viability of handsets with multiple network access modes, others believe the next-generation vision will finally bring the GSM and cdmaOne worlds together.
"This was a onetime opportunity to get close to a common global wireless standard," says Telstra's Young. "And if we messed this one up as an industry, we were never going to get there again because this was the point that we were really going to converge or diverge."
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