Redefining Wireless

LMDS has emerged as an entrepreneurial tool for challenging established LEC domination in the local loop. Some LMDS providers already have entered markets such as Internet services and are providing cost-effective broadband services to small- and medium-size companies. System modularity, reduced dependence on existing infrastructure, fewer connections to the wireline network and a rapid return on investment are bringing LMDS to the forefront of high-speed, information-access technologies. However, considerable differences exist between traditional wireless services and the microwave environment of LMDS.

As PCS providers enter the wireless local loop (WLL) market via mobile and fixed wireless, their competition will come from LMDS providers. Whether you are an LMDS provider or you compete with one, you must consider these issues and how they can affect your network.

Complementary or Competitive?

LMDS and digital PCS networks distribute frequencies to receive points by a cell-type architecture. Digital signaling and effective bandwidth will allow both of these technologies to reach a significant portion of potential customers. Both technologies also rely on backhaul to the wireline provider to access the public-switched telephone network. But the similarities end there. The deployment, allocated frequency, potential market use and flexibility of infrastructure differentiate these two wireless product offerings and define the separate market segments they hope to capture.

The most striking difference between LMDS and PCS is the network bandwidth (or throughput). PCS is allocated 40MHz while LMDS uses a substantial 1,300MHz. This bandwidth, depending on the modulation technique used, can provide data-throughput rates of more than 800 T1 lines to the respective coverage area. FDMA and TDMA formats predominantly are used in LMDS current deployment, while PCS has greater frequency optimization with TDMA and CDMA technologies.

PCS was designed for mobile use. Ideally, PCS customers are within six feet of the ground, and signals are susceptible to multipath fading. LMDS technology requires a stationary condition for the transmitter and receiver. The line-of-sight (LOS) nature of LMDS requires highly directional antennas, which greatly reduces the effects of multipath fading. It also allows technicians to adjust antenna direction after installation for better performance.

Therefore, you can deploy LMDS locations much more rapidly than PCS or wireline services. Equipment for the LMDS base, node and CPE is modular, and you can upgrade it quickly to meet increased demand. Modularity allows you to design deployment to meet initial market demand and reduce cost expenditures for future capacity considerations on the front end of the installation process, which allows for greater return on investment. PCS systems, however, need to plan for the highest estimated usage because of the high cost of deploying hardware and infrastructure.

Deployment considerations for LMDS and PCS also are considerably different. Cell coverage areas for LMDS are smaller than those for PCS because of the nature of microwave signaling. PCS signals are lower in frequency (1.9GHz) and have a greater distribution capability that is not hindered by geographic or atmospheric conditions. LMDS, however, operating in the Ka band, is susceptible to rain interference. Smaller LMDS cell sites (5km radius or less) and variable power-output systems that recognize rain levels have made the 99.99% throughput capacity of the signal deployable in variable weather conditions.

Despite the differences between these two technologies, you should view them as complementary as well as competitive. PCS networks currently are focused on voice delivery with limited success in mobile data with CDPD technology, and not the multiplatform approach that LMDS providers are using to differentiate their products. Bundling voice, data and multimedia services in the LMDS signal provides a different marketing approach from PCS WLL. PCS providers are partnering with CATV providers to extend their coverage areas by using the CATV infrastructure to overlay the analog network with the PCS CDMA signal. This gives PCS providers the ability to reach remote areas more economically. A major consideration in PCS deployment is the financial investment in infrastructure compared with an LMDS deployment. PCS MTSOs, towers and other infrastructure are not as readily redeployable as LMDS systems would be if market demands changed. The ability of LMDS to act as wireless fiber can give PCS operators the flexibility to bypass LEC connections to a CLEC point of presence or their own switching offices.

LMDS Equipment Considerations

One of the unique properties of LMDS deployment is the equipment's modular nature. Using ATM switching allows LMDS to bring multiple services to market without the burden of legacy equipment. Although existing service providers are forced to maximize their investments in current embedded technology, such as copper wire, to deliver new services, LMDS providers can respond to bandwidth demands more quickly.

Equipment-location considerations have a smaller footprint than other technologies. Base-station equipment provides all of the following functions that would traditionally take up an entire floor in the LEC central office: processing, wireline/wireless protocol interfaces, multiplexing, de-multiplexing, compression, error detection, encoding, decoding, routing, modulation and demodulation. The compact equipment allows for rooftop placement, which facilitates service efforts by centrally locating the equipment.

Antenna placement is one of the complicated considerations of LMDS installation. With numerous RF technologies currently demanding antenna space, regulatory groups as well as building owners are hesitant to grant permission for antenna placement. Local legislative actions concerning tower installations could hamper the network design. The need for LOS placement has created areas that are best serviced by a few strategic locations. Shared spaces with other vendors or competitors, however, may increase the chance of vandalism or inadvertent damage to another entity's equipment.

Scaleable and non-scaleable network interface units (NIUs) provide the gateway between the RF component and in-building systems such as PBXs, data networks and video-conferencing equipment. The flexibility of the scaleable NIU allows for quicker configuration changes to meet market demands for increases or decreases in a certain area. Non-scaleable NIUs are not user-configurable. The unit's standalone nature provides greater cost efficiencies compared with the scalable version. The non-scaleable NIU meets the requirements for market segments such as small- or medium-size businesses that are going after T1 or other high-speed access that was cost-prohibitive in the past.

Equipment combinations -- roof-mounted transceivers, NIUs and ATM-switched services -- can reduce an installation's time and cost. The combination of voice, data and multimedia services has brought the need for network management. Various locations within the network are accessed for real-time monitoring, servicing and configuring system-demand cycles. Remote access to NIUs allows the provider to monitor error alarms and re-configure the equipment to compensate for network changes or failures. This flexibility helps reduce service downtime and maintenance costs, and provides a higher level of customer satisfaction.

Another element of system combination is the use of ATM switching technologies for delivery. ATM was designed for multiple technology delivery over the same media. This allows LMDS providers to offer a complete package to the customer in a more cost-effective approach than traditional wireline or cable providers. Embedded providers are in a rapid upgrade mode or acquisition mode in order to be a cross-platform service provider. LMDS providers do not have the legacy limitations to implement newer 2-way interactive technologies. They can reach viable markets faster. The low-cost combining technology for LMDS also allows the entrepreneur to venture into markets that would be too cost-prohibitive for traditional service providers to target.

Bandwidth Usage

With the capability to offer 1.5Gb/s downstream with a 200Mb/s upstream, LMDS has the potential to deliver numerous offerings within a single pipe to subscribers. LMDS can deliver fully interactive television, Internet access speeds greater than current conventional wireline and consolidated network configurations. Because prospective providers have no limitations on the number of licenses they can purchase, other than the restriction on LECs and current cable providers, wide-area networks could be established quickly in key second- and third-tier metropolitan areas.

In addition, the Internet has changed the way companies do business. Major metropolitan areas have been "ringed" with fiber to provide services to existing customers in those areas. High-speed data access has not been cost-effective for small- or medium-size businesses outside of the fiber ring. T1, ISDN or xDSL costs have prohibited these peripheral businesses from reaching the Internet, but LMDS providers could capture the market more quickly and provide more efficient bandwidth allocation by deploying where the demand is high and supply is minimal.

LMDS Considerations

As with any new technology, early adopters are leaders. The microwave technology associated with LMDS delivery is not new, but newer component technologies have allowed it to become more cost effective. Variable power-output systems and overlapping or redundant cell areas have addressed environmental impairments such as rain attenuation and foliage.

LMDS' biggest challenge may lie more in the courtroom than in the airwaves. LECs and current cable providers have challenged the restriction for their involvement in license purchasing for LMDS frequencies. But because of the unpredictable political environment, current licensees may wait for a final judgment before investing. Some LMDS providers, however, could jump ahead of competitors by implementing now instead of waiting, especially in areas that are not under contention.

Most of today's forecast and business plans indicate small- to medium-size businesses as the target market for broadband services, with limited success in the residential market. Despite these forecasts, some companies are going against the grain. Jim Schoenduve, Wytec executive vice president of sales and marketing, said LMDS services can profit in the residential market. Wytec has released a point-to-multipoint system that will allow carriers to offer LMDS services in the residential and SOHO markets. The system's CPE receive and transceive antenna, as well as remote antenna siting that uses RF fiber distribution, make this possible. Wytec's Causeway system is designed to offer services such as broadcast video, pay per view, audio broadcast and video-on-demand.

Douglas Smith, Nortel Broadband Wireless Access COO, also is optimistic about potential in the residential market, noting a demand for high-speed data from high-end households and "technically-advanced families." Angela Kendall, Triton Network Systems marketing manager, said broadband providers shouldn't ponder the residential market right now. They should follow the cellular model and concentrate on high-end business customers.

Larry Schwerin, Lucent Technologies general manager, added that today, other solutions such as DSL and cable modems offer more cost- effective solutions for the residential market.

By Karissa Todd