Connecting the dots with broadband wireless

To some, it’s the perfect solution to the problem of the “last mile.” To others, it’s merely a nice idea that is years away from being useful.

Broadband wireless, or fixed wireless to the world’s governments, has lately been hyped as being everything from a complement to competition to wired fibre networks.

Ultimately, broadband wireless is a vision, according to John Sydor, the manager of broadband wireless for Canada’s Communications Resource Centre.

“What broadband wireless primarily is the desire by people to have the sort of (wireless) connectivity with their computers as they have within buildings using Ethernet or wired beta links,” he says.

To Sydor, that translates into fast data transmission rates and the possibility that one day service providers will be able to offer up bandwidth hungry multimedia applications.

“Ideally, what we want to do with broadband wireless is we want to make the (technology) such that you can download videos,” he describes. “This is the holy grail of the Internet – to be able to transmit videos in an Internet format between users. The Internet is moving from being a textual-based format to a video-based format.”

For the Canadian government, however, broadband wireless offers considerably more opportunities than mere Internet video transmission. John Manley, the Minister of Industry in Canada, has for years supported broadband wireless as a cure-all to the nation’s communications problems, including being an answer to the stranglehold that cable television companies have held on the marketplace.

However, though residential customers may salivate at a future of lower phone, Internet and television connection costs because of increased competition, most experts believe broadband wireless is more likely to benefit the business market.

Companies with wireless spectrum in the lower frequencies do offer residential customers Internet, long distance and television services, Sydor admits, but he says these carriers simply don’t have enough bandwidth to offer the enriched services people are going to want in the future. And in the higher frequencies, enterprise network vendors like Nortel say they have given up trying to manufacture broadband wireless equipment cheap enough for residential customer cost points.

To the small and medium-size business market however, broadband wireless offers plenty of opportunities to quickly, and at an increasingly low cost, improve the speed and efficiency of a network.

How fast? Anywhere from typical T-1 speeds in a LAN to OC-3 speeds in a WAN.

How cheap? In some cases up to 40 per cent lower than subscriptions for comparable service from a land-based service provider, according to Telechoice, a market strategy consultancy for the telecommunications industry.

Of course, there are drawbacks. For a wireless network, broadband wireless isn’t very good at connecting mobile, hidden or far-away objects.

On the other hand, as more and more cities begin restricting the amount of companies they allow to rip up roads and lay fibre in downtown cores, companies may begin to find the best way to connect their offices to the Internet backbone is through an antenna on their rooftop.

It’s important to delineate at what point in the wireless spectrum broadband wireless begins. Cellular and digital phone providers have been promising broadband services when 3G technology becomes available within the next year or two. But Sydor says that the data rates 3G enables, just over 100Mbps, fall far short of true fixed wireless.

“A good rule of thumb is if it can carry 10base-T or 100base-T Ethernet links. If it runs at slower speeds, it’s not really broadband, it’s more or less conventional data,” he says.

If that’s the case, then broadband wireless really starts in the 2.285Ghz to 2.4835Ghz frequencies, generally called the 2.4Ghz band. The point-to-point links that are established in this licence-exempt, or spread spectrum, band can span distances of several hundred feet to several miles.

Manufacturers have been producing technology for wireless LANs (WLANs) in the 2.4Ghz band for years. However, a slow connection speed of less than 3Mbps prevented most enterprises from taking a chance on the technology. However, a new industry-wide specification agreed upon earlier this year, the IEEE’s 802.11b, has led to a boom in WLAN systems. Carrying data rates of 11Mbps in the office, and 1Mbps between PCs, access point products and Ethernet cards have been “flying off the shelves,” according to Iain Grant, the managing director of The Yankee Group in Canada in Brockville, Ont.

Except Nortel, almost all the major networking vendors now offer some sort of WLAN system, including Lucent Technologies, Cisco Systems, Inc. and 3Com. Many systems also now carry the “Wi-Fi” logo, presented by the Wireless Ethernet Compatibility Alliance, indicating the product is interoperable with WLAN products from other Wi-Fi vendors.

“The thing that’s most exciting about that band is that 802.11b is a common specification, and there’s common chip sets to let equipment run on that band, which means the price of broadband wireless is dropping considerably” Sydor says.

The only problem with 802.11b and 2.4Ghz LANs is the protocols are inefficient, he says, meaning the capacities drop off dramatically as a company adds more computers to its network. Therefore, 11b WLANs are currently useful mainly for the small office set.

That could change in the next couple of years, though. Sydor says the wireless industry is now working on a new specification, dubbed 802.11a, that purports to carry data rates of up to 54Mbps.

But whether 802.11a WLAN devices will exist in the 2.4Ghz band is another story. As a licence-exempt band, 2.4Ghz is pretty crowded. In Canada, the band is classified for use by Industrial, Scientific and Medical (ISM) radio frequency devices, which basically means your microwave oven at home could be cooking your food on the same band as your home office network runs on.

One solution North American governments are discussing is opening up some of the licence-exempt bands in the 5Ghz range for WLAN technology.

“I was at an IEEE meeting in Denver, and they look upon those bands, at least in the 5.25Ghz to 5.35Ghz and the 5.725Ghz to 5.825Ghz ranges, as being very viable broadband licence-exempt bands,” Sydor says.

Slightly above the 2.4Ghz band are what’s known as the MMDS (multi-channel, multi-point distribution service) bands. In Canada, these licenced bands are more frequently called MCS (multi-point communications system) in the 2.5Ghz to 2.596Ghz range and MDS (multipoint distribution system) in the 2.596Ghz to 2.686Ghz. Both frequencies are supposed to enable service providers to offer consumers a variety of two-way services with voice, data, multimedia and broadcasting applications.

Industry Canada only issued licences for operators in the MDS band in March of this year. But MCS operators like Look Communications have been selling their wireless analogue and digital television services as well as high speed Internet services for the past couple of years. Although television service, a one-way broadcast, works well on MMDS, Sydor says that is not the case with Internet services.

“The inherent Achilles heel with MMDS is that (operators) don’t have enough bandwidth,” he explains. “On a wireline, if you’ve got DSL, you have a link directly to your home and you’ve got a certain amount of capability given to you, like 1Mbps. That’s your capacity.

“Many of these MMDS carriers, they give you 6Mbps to your home but you’ve got to share that with several hundred other users or more. MMDS’s primary use right now is television.”

And broadcasting television is apparently what Canada’s government wants MMDS to do anyways. Four years ago, the federal government issued licences in the 28Ghz range to three companies. According to Earl Hoeg, the manager of wireless communications for Industry Canada, the government saw this band as being the “third lane to the information highway.” Specifically, operators were expected to develop technology to compete against the existing cable and telephony companies.

The problem was that there was no off-the-shelf equipment available to enable providers to offer those services. LMCS (local multi-point communications systems) technology was at the time still military technology. So the government moved on and issued licences in the MCS band, which left folks wondering what services LMCS bands would be able to offer.

The answer, as North America is now becoming aware, is metropolitan area networks (MANs) – a possible solution to last mile bottlenecks. Industry Canada completed its first wireless auction for spectrum in the 24Ghz and 38Ghz range last year, collecting $171 million from companies eager to provide alternatives to the fibre carriers.

Toronto’s Stream Intelligent Networks, Canada’s biggest 38-Ghz licence holder, has recently started to offer point-to-point broadband wireless connections with throughput rates of 155Mbps, or OC-3 levels. The company hopes to have radios in service by the end of this year operating at 625Mbps – the OC-12 rate.

“This product enables us to deliver a large amount of fixed bandwidth from one point on our network to a customer’s premises and interconnect that customer (usually carriers and service providers) to our network,” explains Bob MacCallum, vice-president and CTO for Stream. The technology, which sells in the range of $6,000 monthly with a one-time installation charge, operates on the 38Ghz band but it does not yet provide for point-to-multi-point connections.

In fact, despite being called LMCS, vendors have been slow in developing point-to-multi-point technology for the 24Ghz to 40Ghz bands. Likely, it is because they have been too busy making sure point-to-point equipment is able to overcome some of the shortcomings of such high wireless frequencies. For example, the wireless signals were initially tenuated significantly by rain, but carriers are now able to program their radios to boost power to the signal to ensure delivery in wet weather.

Stream says its “wireless-in-a-box” offering guarantees carrier-grade reliability, or 99.999 per cent. However, the maximum distance a signal can “hop” is 2.3 kilometres.

But Sydor doesn’t believe that fact will dampen the enthusiasm for broadband wireless as the perfect way to skip past last-mile traffic.

“Most companies are simply interested in providing that backbone link,” he explains. “Inside a typical office, if you’ve got 10 computers, you just put an Ethernet switch in and you’ve got that broadband link – one computer can communicate to another at 100Mbps, that’s not a problem. It’s trying to get off that office floor…and get it down to the other side of the city to the other office, that’s the link that’s non-existent.

“When you get a (wireless) link established to your business, especially building-to-building, you will have a high-quality link that will be more effective than wireline, in terms of the fact you don’t have to worry about a cable being cut,” he says. “And you’ll always get a higher bandwidth available to you.”