Don't think this has ever been posted and it's interesting.Dated 10/5/98. If it has, well...
Wireless Industry Fragments In Approach To Data
Multiple options win support for both short-term and long-term network needs
By Fred Dawson, Contributing Editor
Technology Watch
The hotter high-speed data gets in the eyes of mobile wireless service providers, the bigger the impediments they seem to be putting up against efforts to achieve the scale efficiencies that are vital to success.
Individual wireless operators are exploiting proprietary technology breakthroughs by various vendors to gain advantages over competitors in bringing faster data services to market, even though they risk losing the economies of scale that would accompany standardized approaches.
To date, fragmentation has been a well-documented point of struggle in the International Telecommunication Union's efforts to create a so-called third-generation (3G) framework for global interconnection of personal communications services (PCS) and cellular networks. Now it also is affecting efforts at consensus on nearer-term evolutionary steps within various air interface groups as well.
Doug Brandon, vice president of external affairs at AT&T Wireless Services Inc. (www.att.com/wireless), is bluntly honest about his company's attitude toward efforts to accommodate the worldwide push to 3G, where the goal is to support mobile access at 384 kilobits per second and fixed access at 1.5 megabits per second or higher with allocation of additional PCS spectrum. "We wouldn't like to see a lot of regulation done to level that playing field," Brandon says. "3G is kind of a stalking horse for European carriers who are spectrally challenged."
Different Upgrades
AT&T engineers, making use of the IS-136 Time Division Multiple Access air interface, have come up with a way to get to a "3G type of capability" by 2000 or 2001 through a series of relatively painless upgrades of existing infrastructure using only 2 megahertz of spectrum, Brandon says. This contrasts with the 5-MHz channelization required for 3G performance under Wideband Code Division Multiple Access (W-CDMA), proposed as a platform by the non-U.S. providers of global system for mobile communication (GSM) service, and under CDMA 2000 -- also known as CDMAOne --he air interface backed by operators that now use IS-95.
AT&T isn't alone in looking after its own interests first. As the ITU strives to reach consensus on the 3G framework, there is growing factionalization within various air interface groups on the question of which paths to take in the so-called 2 1/2 G evolution to 3G, where the nearer-term target is introduction of 64-Kbps data service next year, followed by 128-Kbps service a year or two ahead of full 3G implementation.
The CDMAOne camp, after working to push what is known as IS-95B to completion as a standard earlier this year, appears to be losing interest in this system, which, among other things, will support data access over widely deployed CDMA infrastructure at 64 Kbps without requiring hardware upgrades. Other options now capturing operators' attention are prompting many vendors to back away from introducing IS-95B systems.
"While higher data rates are desirable, IS-95B uses so much voice capacity, we don't see where the business case is," says David Murashige, vice president of CDMA marketing and product management at Northern Telecom Inc. (www.nortel.com). "There's still a lot of uncertainty about what the right solution is going to be, including whether the whole idea of 3G is the right approach."
At this point, only one infrastructure vendor, Motorola Inc. (www.motorola.com), supports IS-95B. Meanwhile, many of the suppliers that were supporting IS-95B have shifted to another new CDMA-based standard, known as IXRTT or CDMA 2000 Basic. IXRTT will deliver data simultaneously to four to five users over a 1.25-MHz channel; IS-95B accommodates only two users per 1.25-MHz channel.
IXRTT could be pegged to deliver 144 Kbps rather than 64 Kbps by the time the draft specification is completed early next year. It will require some hardware upgrades, consisting of changeouts of application-specific integrated circuits (ASICs).
Growing support for IXRTT creates real problems for IS-95B, Murashige says, because there's no easy upgrade path from that platform to IXRTT.
Adding further to the confusion over the evolutionary path to wireless high-speed data is still another interim, pre-3G technology announced in late September by Qualcomm Inc. (www.qualcomm.com). Qualcomm's High Data Rate (HDR) system, like IXRTT, would require base station ASIC changeouts, but it would deliver much greater throughput, offering data bursts of up to 2.4 Mbps.
HDR operates on a contention basis, which means that users don't gain access to a fixed data channel, as they do with other interim techniques. Instead, users contend for time slots in a larger time division packet data stream, with data rates going down as more users contend for bandwidth, says Irwin Jacobs, chairman and chief executive officer of Qualcomm. "It's like an Ethernet but without collision, which means you can support a lot of users," he says.
Unlike 3G systems, which are designed to support voice and data access over the same 5-MHz channel, the HDR system requires allocation of one or more of the IS-95 1.25-MHz channels to data only. This is a better way to maximize data efficiency, Jacobs says.
"With data, you can burst out packets at very high rates and pass around access to multiple users," Jacobs says. "You don't have to compromise data efficiency the way you do when you share the channel for voice and data."
Qualcomm demonstrated the new system at last month's PCS '98 convention in Orlando, Fla., using upgraded versions of its IS-95 base stations. The company used field programmable gate array circuit boards or "emulators" instead of ASICs, which it anticipates will be ready for HDR upgrades in field tests by the middle of next year, with commercial rollouts to follow by the end of 1999.
Qualcomm must find vendor partners to license the technology, including handset and other terminal suppliers, none of which has stepped forward publicly yet to back HDR. "There are obvious complications with a proprietary new air interface specification when you don't have any sense of how much support there's going to be," Murashige says, adding that Nortel "hasn't closed any discussions on HDR with Qualcomm."
Data Only?
Clearly, though, something new is happening in the wireless industry's thinking about data, where the idea of opening up a pure data channel is making ever more sense to ever more people. Merle Gilmore, president of the communications enterprises unit at Motorola, says the industry is barking up the wrong tree when it couches its thinking about the evolution to data in conventional telecommunications terms.
What carriers should focus on is the transition away from hierarchical architectures dominated by circuit switching to a distributed Internet Protocol (IP) packet-switched architecture, Gilmore says. "This will facilitate a single architecture capable of delivering the voice services and the data applications whether you're using GSM, CDMA or any of the new standards that are being proposed," he says.
Without recognizing the cost-benefit imperatives behind integrated IP telephony and data communications, the wireless industry runs the risk of repeating the mistakes of wireline carriers that now are struggling to get out from under the weight of their circuit switched architecture, explains Matthew Desch, president of wireless networks at Nortel. "IP technology as a basis for the network is a very, very cost-effective technology," he says, adding that this means data applications will become "add-ons to a much lower-cost voice network."
Right now, wireless carriers are primarily focused on exploiting data as a separate service in the best ways they can using existing infrastructure, says Greg Williams, vice president of wireless systems at SBC Technology Resources Inc., a unit of SBC Communications Inc. (www.sbc.com). In fact, he adds, SBC is using GSM for data within its Pacific Bell Mobile territories and IS-136 over its Southwestern Bell Wireless territories.
"You're going to see a lot of 2 1/2 G services coming out quicker than people think," Williams says. "My company is a strong supporter of the family-of-standards approach because we and a lot of others are going to move into data within our existing bands."
Babel Abounds
By focusing on development of network interconnection protocols to link all types of wireless infrastructures rather than seeking uniformity among a proliferation of air interfaces, the industry will be able to get beyond the tower of Babel that the search for a common standard has become, according to Williams and other backers of this idea.
But even this de facto recognition of balkanization doesn't go far enough toward achieving what's needed to exploit the data opportunity, says Bill Wiberg, president of advanced mobile phone system/PCS wireless networks at Lucent Technologies Inc. (www.lucent.com). Carriers chasing after advantage with proprietary air interface and data access technologies without driving universal agreement on the wireless data infrastructure are risking a high-cost, low-return segmentation of the market that could make data the nonstarter it has always been in the wireless business, Wiberg says.
"The ease-of-use issue has to be worked out, and the way it can be worked out is through partnering among the different members of the industry, working together to bring something that's both compelling and simple to the end user," he says.
Nortel's Desch says he's optimistic the industry will get its act together on data because it's starting to recognize where the market power of packetization really resides. "Data applications are exciting," he says, "but the business case revolves more around cost than anything else.
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