Wireless protocol battle takes shape
Wireless service providers want you to be just as productive on the road as you are in your office. Now if they can just work out their conflicting standards...
Executives now spend more time on the road--meeting customers, attending trade shows, examining new products--than ever before. However, a disconnect has occurred between the work a person can do at his desktop and that which is possible when traveling. The latter tends to be more unproductive because employees have no easy way to connect to corporate networks. Wireless service providers would like to solve this problem by adding more bandwidth to their networks. Many plan to boost top transmission speeds from tens of Kbps to multiple Mbps in the next few years. In this article, we'll explore the ongoing development of high-speed wireless data services.
Lack of consensus
Increasing need for wireless data services
Although business travelers rely heavily on wireless voice connections, the same is not true with wireless data services. "Acceptance of wireless data technology to date has been limited to select niches (fleet management, courier systems), and it has had little or no impact on business users," stated Ira Brodsky, the president of Datacomm Research Inc., of Chesterfield, Mo., a market research firm that focuses on wireless communications.
With the workplace dramatically changing, the need for these services has been growing. As executives travel, they want to be able to check their electronic mail so "out of office" will not mean "out of touch." "With Internet technologies becoming more engrained in daily business applications, executives have been searching for ways to surf the Web while on the road," stated John Marinho, director of the wireless network transmission group at Lucent Technologies Inc., of Murray Hills, N.J.
Currently, this is not an easy task for a variety of reasons. Slow transmission speeds have been a deterrent: Wireless data networks now operate with a top speed of 19.2Kbps. And because these networks rely on sophisticated error-checking techniques that eat up bandwidth to insure data delivery, actual throughput is often much less--as much as 50 percent less than advertised. So, working with a complex graphic file is difficult, and downloading a Microsoft PowerPoint presentation or a video clip is just not practical now on wireless networks.
In addition, wireless data networks were designed to support proprietary protocols rather than IP. As a result, applications must be rewritten for wireless connections--a process few software companies have undertaken.
Consequently, wireless carriers want to boost transmission rates from tens of Kbps to a few Mbps and have their networks work with IP. With these changes, users would be able to rely on wireless networks for Web browsing, electronic commerce, virtual private networking, and even video transmissions.
Although all carriers see the need to move to a new infrastructure, the proper standard is not as clear. Rather than taking a simple path, carriers are splintering in different directions and creating a handful of incompatible transports for next generation wireless voice and data networks.
The Federal Communications Commission has played a role in this problem. Instead of adopting a single standard for the entire country--a common process abroad--the agency has allowed wireless operators to install whatever equipment they want. The result is a growing palette of incompatible services.
TDMA vs. CDMA
Today's wireless networks can be divided into two types of circuit switched connections: time-division multiple access (TDMA) and code-division multiple access (CDMA). TDMA, the older of the two, relies on multiplexing to divide bandwidth into distinct sections for each call. CDMA transmits simultaneous signals over a shared portion of the spectrum, which can provide three to five times the calling capacity of a TDMA network. The less efficiently an operator uses available wireless spectrum, the fewer calls it can support per cell site; this limitation forces a carrier to split its sites into smaller subdivisions, thereby driving up its infrastructure costs.
In addition, TDMA requires carriers to upgrade their networks twice to get from current low-speed to multi-Mbps connections, whereas CDMA is a one-step process. AT&T Wireless Services Inc. (Kirkland, Wash.) is firmly backing TDMA technology, but other wireless carriers are looking to CDMA for more bandwidth.
However, multiple versions of CDMA are emerging, and they use different wireless frequency bands and protocols for packaging information. Wideband-CDMA (W-CDMA) is designed to run in the 2GHz frequency range, which has not been used for any wireless systems to date. Thus, carriers are assured of cleaner connections than those in other bands, which share frequency ranges with devices like garage-door openers and television remote control systems.
But because they operate in a new, high-frequency range, W-CDMA services require sophisticated, expensive network equipment. Carriers also must operate two separate networks--one for low-speed connections and a second for higher-speed links.
In addition, government agencies must make the bandwidth available to carriers. Doing so usually involves a complicated bidding process that increases carriers' costs. Although the process has been taking place in other countries, there hasn't been much activity in the U.S.; foreign carriers are further along in W-CDMA deployments. NTT Mobile Communications Network Inc. (Tokyo, Japan) has been testing W-CDMA for the last two years and expects to launch commercial services later this summer.
Domestic carriers are more interested in CDMA-2000, which operates in existing cellular and personal communications services spectra: 800 to 900 MHz and 1.8 to 1.9 GHz. By staying in these ranges, carriers avoid the bidding wars associated with new frequency ranges. They can also maximize their investments by layering new services on top of existing ones rather than building two autonomous networks.
A couple of options are emerging for moving from CDMA to CDMA-2000 networks. Qualcomm Corp., of San Diego, Calif. has been a leading provider of CDMA technology. It has offered its High Data Rate (HDR) protocol, which supports 2.4Mbps transmissions, as a migration path.
Verizon Wireless of New York, and Sprint Corp., of Overland Park, Kan., are basing their networks on Qualcomm's protocol. "We think CDMA-2000 HDR offers the least disruptive upgrade path for our network," stated Oliver Valente, vice president of technology and advanced system development at Sprint.
In March, Motorola Inc., of Schaumburg, Ill., and Nokia Ltd., Espoo, Finland, proposed an alternative. The 1Xtreme protocol is designed to support multimedia communications at speeds up to 5.2Mbps. "While Motorola and Nokia have taken an interesting technical approach, it may be a little late in the game for their protocol to gain much acceptance," stated Datacomm Research's Brodsky. The companies are gambling that because few carriers now offer next generation wireless services, they will be willing to deploy the one that provides users with the most bandwidth.
Whether that is a sound deduction will become clearer in the coming months. "Carriers have begun testing next-generation wireless data equipment with the goal of rolling out new services near the end of the year," said Peter MacLaren, vice president of strategic marketing at Nortel Networks Inc., of Ottawa, Can.
Such plans depend on equipment vendors' ability to deliver new products that support high-speed data transmissions. "We've had next-generation wireless products in our test labs for a few months and are confident that equipment vendors will soon deliver products capable of carrying customer traffic," said Sprint's Valente.
However, it looks like these services will rely on multiple infrastructures. "I don't expect all of the proposed high-speed wireless data standards to gain broad acceptance but it's too early to determine which will be widely deployed," said Datacomm Research's Brodsky.
New service possibilities
Once carriers make their selections, they will concentrate on new services. "With high-speed networks in place, carriers will be able to offer a variety of rich information based services," said Northern Telecom's MacLaren.
Already, some carriers offer services, such as stock quotes and sports scores; however, the content is limited to simple text messages. Now, cellular phone and Personal Digital Assistant suppliers are working on handheld devices that include microbrowsers, so users will be able to surf the Internet and download graphics and video images.
Carriers expect a variety of companies from auto manufacturers and airlines to financial firms and utilities to develop new content for the high-speed connections. For example, wireless database access would provide salespersons with the ability to check prices and delivery dates, enter orders, and even take payments-without stepping outside the customer's office. Doing so would improve their sales rate, eliminate paperwork (and low-level administrative positions), improve customer service, and speed cash flow.
Such benefits are one reason why vendors expect wireless data services to gain significant acceptance in the next few years. "High-speed wireless data services fit well with how executives now conduct business," concluded Lucent's Marinho. "Once the underlying infrastructure is in place, users will find plenty of ways to exploit it--some we haven't even envisioned yet."