Unwiring the Local Loop
By Carlo Longino, Tue Apr 22 08:00:00 GMT 2003

Vendors are cherry-picking mobile standards to create Wireless Local Loop gear.


Incumbent local telcos and cable-television operators have long had a stranglehold on their customers, simply because they control the wires running into their homes and offices. No matter what regulators intended when they ordered these companies to share their infrastructure, one new competitor after another has fallen by the wayside, unable to loosen the incumbents' grip on the network.

Wireless was always looked to as a solution to this problem, but most of the first ideas for Wireless Local Loop (WLL) networks were felled by technological constraints; most required line-of-sight connections that had to be set up by a professional radio engineer and kept accurately aimed. But as wireless technology has matured, it's again being looked at as a way to bypass those incumbent operators and their local networks, and most of the flaws of early systems have been removed. But what's interesting is that many of these networks are actually based on mobile standards like UMTS.

Who Needs Handoffs?


One of the main sticking points in the development of UMTS is getting networks to adequately handle hand-offs. For a mobile network, this is of paramount importance, but for a fixed WLL system, it's not really necessary. So Soma Networks, one company developing such equipment, just junked that bit of the standard, leaving it for the mobile gear manufacturers to work out, along with other demands on the standard like battery life.

Soma's network design solves many of the issues plaguing early fixed wireless gear. Customers simply buy or rent a "Somaport" network appliance, take it home, and plug it in. The box doesn't require a line-of-sight connection or an antenna, and sets itself up to use the network automatically without user intervention. It also supports self-provisioning whereby users can simply go online and change their service around or add additional features.

Soma isn't the only company adapting mobile standards to fit the market. Texas-based Navini Networks has a proprietary standard closely related to UMTS, while Silicon Valley company IPWireless has also cherry-picked UMTS, retaining mobility but dropping voice. But both of these companies see their product fitting in to the potentially huge fixed-broadband WLL market.

For most general consumers, mobility would be little more than an additional feature or competitive advantage, not the main selling point of the wireless service. Navini's CEO has described his company's technology as "nomadic", meaning users can connect from anywhere in a covered area, but not while they're moving. He doesn't see this as a serious obstacle to attracting most home users.

But one thing these manufacturers' technologies and networks must support is the incumbent carriers' bread and butter: voice services. In the fixed-line world - just like in the mobile one - voice is the cash cow, where the majority of revenues come from. While approaching voice service in different ways, all the vendors are building in some sort of quality-of-service method to give voice the highest priority. Soma, whose box allows users to simply plug in a standard analog phone, gives voice its own circuit, while most of the other manufacturers are using VoIP systems with network-level QoS. This also means they can ensure that speed and other service guarantees are honored, something that posed difficult for MMDS providers.

Smart Little Network


But there's no doubt that WLL systems are coming, and will make a big impact. NTT Communications (DoCoMo's wireline parent) has a wireless system up and running using Soma technology, Sprint is trying out Navini gear in the US, and IPWireless has several carriers up and running with its technology. But perhaps the most impressive WLL system is Xiaolingtong, or "Little Smart," a Chinese network run by China Telecommunications and China Netcom with equipment from US vendor UTStarcom.

Xiaolingtong has attracted over 20 million subscribers in just two years, most of which are attracted by the service's low cost (about 1.3 cents per minute, versus nearly 5 cents per minute on a mobile). The service uses UTStarcom's Personal Access System (PAS) technology, which is based on the Personal Handyphone System that gained quite a bit of success in Japan. UTStarcom says PAS fills a unique - but vast niche - offering low-cost basic voice and data services to areas without widespread POTS networks, and filling in between POTS service and full-fledged mobile telephony.

PAS networks offer limited mobility - coverage networks aren't nearly as big as cellular networks - that cater to users who make most of their calls from one geographic area, though not necessarily one particular location. Users can also roam from one PAS network to another, so for instance a user in Taiwan can travel to Japan and use PHS networks there.

In China, though, government regulators treat Xiaolingtong as an extension of the carriers' fixed-line networks and won't allow roaming in other cities. But UTStarcom is working on a handset that will work on both their PAS networks and GSM mobile networks, offering the benefits of both - the low cost of using PAS networks when they're available, as well as the geographic reach of GSM networks.

It's cheap and easy for carriers, too. One estimate puts the cost of adding a Xiaolingtong subscriber at USD 80 per line, while adding a fixed-line subscriber at USD 180. And a PAS network can be deployed in a city covering 10 to 12 million potential users in just 3 to 4 months.

Xiaolingtong's only obstacle may come from the government, not from competitors. The service has already sparked price wars and deep drops in Chinese mobile carriers' stock prices. Those carriers in turn are turning up the heat on the country's Ministry of Information Industry to start treating the service as a mobile network and drop its hands-off regulatory approach.

Carlo Longino is a freelance writer based in Austin, Texas. His previous experience includes work for The Wall Street Journal, Dow Jones Newswires, and Hoover's Online.