By Harriet Meyers
Attend any industry conference or skim through a wireless publication and you're bound to stumble across a discussion of 3G (third generation wireless). Standards are being negotiated, and spectrum issues remain unsolved. But a rapidly changing marketplace is directing immediate focus on the requirements of coverage and capacity. And while 3G standards and technologies may eventually satisfy these requirements, wireless operators cannot, like Scarlet O'Hara, say: "I'll think about it tomorrow."
Cellular and PCS operators have already invested billions of dollars in embedded infrastructures. They need to maximize their return on that investment if they are to be financially ready for 3G. They must address the expectations of today's consumers or risk losing their customer base. And they must differentiate themselves from their competitors to hold onto their market share and to increase it.
"The incredible emphasis on 3G during the past year has been astounding," says Perry LaForge, executive director, CDMA Development Group(CDG). "While operators appreciate 3G's potential, their financial reality is in today's investments in today's market."
Consumers continue to base their judgement of what constitutes good value in wireless service on clear and reliable call transmission and continuous and extended coverage. These two characteristics are the most important to all consumers, regardless of age, sex, occupation or level of wireless phone usage, reports Peter D. Hart Research Associates in The Wireless Marketplace in 2000, a study carried out for the Cellular Telecommunications Industry Association (CTIA).
"What customers want today is anytime, anywhere service," says Bill Stone, executive director network planning for Verizon Wireless. "We are also operating under the assumption that the demand for data service is building at this very moment, and that we need to offer customers simultaneous access to voice and data."
As workers become more mobile and rely more heavily on wireless data their expectations, similar to voice, will be for anywhere, anytime, quality service which is fast and easy to access. Capacity and coverage requirements for the network will continue to grow.
Access to data
"The flexible migration of cdmaOne provides a series of upgrades leading to 3G CDMA2000, allowing each operator to upgrade when its individual market requirements dictate," says LaForge. "For some operators, the migration path may never need to reach 3G. However others, such as those in Asia, have a more immediate need for 3G." "We definitely think customers want the wireless web, and we are aggressively deploying the technology to handle it," says Jeff Chaltas, spokesman for Sprint PCS. Sprint PCS will be deploying its 1XRTT network during the second half of 2001. "It should double our voice capacity and increase our data rates ten-fold. But we do not expect to need any forklift changes in our base stations."
"Our current actions at Verizon include continuing the conversion of our existing spectrum from analog to digital, adding more digital carriers as we free up spectrum, adding cell sites to increase the capacity of the network and taking advantage of new technology," says Stone.
"One of the dilemmas for operators today when they try to plan for enough capacity is that there are still so many unanswered questions about data services," says Neal Gorenflo, a senior analyst with the Personal Communications Industry Association (PCIA) . "What will the data model for business services be? How will they price data services? Who will provide the content? And what exactly is the demand? All of the answers to these questions have implications for capacity."
"This is a very complex issue," agrees Stone. "At Verizon we are looking at the worst case as well as the best case. There is a potential for a great deal of growth, and we have to be ready." But what is on offer now to help guarantee that readiness? Dave Bolan, vice president, marketing of Repeater Technologies, believes his company's solution offers more than one advantage. He says: "The lowest-cost way to provide coverage outside of a city is with the use of repeaters."
His company advocates RepeaterHybrid Networks (RHN) to be utilized in suburban and rural areas and rural highway topologies when RF coverage is the primary driver. The RHN is a new application of repeaters which uses a mix of base stations and repeaters. The base stations are used for capacity and core coverage, and the repeaters spread that capacity over a greater coverage area. "As wireless customers travel outside the city to the beach or the mountains, they expect their services to go with them. The advantage of this method is that we are utilizing the technology that is already in the base station," says Bolan. "And when the technology is upgraded, no adjustments to the repeaters are required since they are already 1XRTT compliant." But what about indoor coverage? "Customers want coverage everywhere, including inside buildings, and that is a requirement we cannot ignore. CI Wireless focuses on providing the means to meet the need for RF signal distribution in buildings, and outdoors where coverage or additional capacity is required," says Dave McKay, president of CI Wireless. CI Wireless offers the EkoLite fiber optic in-building system which is designed to provide RF coverage throughout a building or a campus of buildings. It is compatible with all protocols and can be upgraded to a dual-band system.
CI Wireless also offers an over-the-air repeater that enables wireless remote use of base stations directly on frequency. In addition, it provides a fiber optic RF distribution system that utilizes wave division multiplexing to reduce fiber requirements while providing RF links between a campus of buildings. "Fiber-based repeaters are excellent for extending coverage to tunnels, airports and hospitals, while our over-the-air solutions transfer into buildings or other dead areas," says McKay.
"As people begin to use the wireless devices for multiple tasks, we must have complete and perfect coverage for voice and data," says John Spindler, director of product marketing for LGC Wireless. "Whether you are sitting in an airport, a meeting room or a hotel lobby, you'll want to have wireless services available."
LGC provides a fiber-based solution which is now in use in the world's tallest buildings in Kuala Lumpur, Malaysia. "It used to be that the way to get your coverage was to drop a microcell into the facility, using coaxial cable running to a passive antenna structure," says Spindler. "But coaxial cable is expensive, tough to pull and has limited coverage. Our system uses multi-mode fiber which is easy to install and to upgrade. Our solution also lets carriers optimize their use of the spectrum, providing clear and consistent wireless access to voice and data content."
Enhanced voice coders (or vocoders), by contrast, provide a somewhat different solution. They offer operators another method of making their embedded base work harder. The vocoder takes voice and puts it into a digital signal to transfer across the network. CDMA first rolled out 8 kilobit vocoders, and then 13 kbits became the standard. "The latter better represents the voice signal, but impacts the capacity of the network," says Jim Takach, director of advanced programs for the CDG. The latest enhancement to vocoders is the Enhanced Variable Rate Vocoder (EVRC), now being utilized in Korea. EVRC provides 13 kbits voice quality at 8 kbits data rates.
In a CDMA wireless system, capacity, voice quality and coverage are interdependent. Speech compression between the mobile and base station helps maximize the number of simultaneous calls that can be handled at any time in a specific frequency spectrum. The higher the compression ratio, the lower the noise contribution of each call-so system capacity improves. EVRC's flexibility allows it to vary according to the noise on the system at any given time. "Verizon has implemented EVRC in a substantial portion of our network," says Stone.
"EVRC provides greater voice quality with the least resources," Takach says. "Vocoders are definitely a source for improving the capacity of the current network."
A new solution-although one long established in GSM networks-is SIM cards. CDMA now has a SIM card standard. SIM, or smart cards, are microchip-embedded cards inserted into handsets. Each card contains specific data on one subscriber and can be used in various phones. China Unicom, which is installing a CDMA network, plans to use the cards so its subscribers can roam between the new CDMA network and its older GSM network. SIM cards offer CDMA operators the ability to extend their coverage to customers-giving them the capability of roaming with other technologies.
Then there's 1XRTT, for which there are high hopes in the cdmaOne community, although there is also some disagreement as to whether 1XRTT is a 2.5 or a 3G solution, and whether it offers a short-term fix or a long-term answer. But the differences appear to be mostly a matter of semantics. 1X has been defined as the first phase of CDMA2000, the third generation evolution of cdmaOne. It uses 1.25 MHz of bandwidth and offers packet data and voice access speeds up to 144 kilobits per second.
"1X is designed to leverage the investments operators have already made in equipment," says Louis Pineda, Qualcomm's vice president of product management. Qualcomm is preparing for the transition to 1X with High Data Rate (HDR) technology. HDR provides high-capacity data access by providing up to 2.4 Mbps in a 1.25 MHz channel. Qualcomm also developed the CSM 5000TM Cell Site Modem for CDMA base stations. "The chip provides up to twice the overall capacity of voice users over IS-95A and IS-95B systems, and supports up to 32 simultaneous users on a single chip," says Pineda.
"We are planning a very aggressive rollout of 1XRTT at Verizon," says Stone. "It offers the potential for twice the capacity gain in voice, and we need that capability." Sprint PCS is trialing 1X technology now, and plans a deployment next year, according to Chaltas.
"1X is a long and lasting solution-with a finite amount of spectrum you get a lot in the way of capacity," says Takach. "All it takes for an existing CDMA operator is a channel card and some software to help manage the transition of new users into the network."
However, even with all of these solutions to coverage and capacity, the real key to handling a great deal of additional capacity required to handle the data access which is anticipated over the long haul is bandwidth. In Japan, the Ministry of Post and Telecommunications is willing to allocate additional spectrum for wireless growth only if those systems offer 3G technology. Subscriber growth and data usage in Japan is unprecedented, driving the Japanese operators to move aggressively to 3G, focusing on WCDMA, in order to get the spectrum to handle this growth. "If we experienced that kind of take up in data customer in the U.S., I don't know how we'd handle it," says Desautels. "On the other hand, that's not a bad problem to have."
In the U.S., CDMA2000 awaits the availability of more spectrum. The Federal Communications Commission plans this year to auction two bands of spectrum. But wireless operators are concerned that the actual availability of this spectrum could take years since 84 television stations now broadcast on that spectrum and 54 others have the right to broadcast. Wireless operators have also expressed concern that wireless networks and television channels from Mexico and Canada could cause interference. FCC chairman William Kennard recently said that the FCC plans "to ensure that the deployment of new wireless applications can be accomplished quickly."
"All of the technologies today are addressing the same issues of coverage and capacity," says Takach. "And while there's a lot of hype around 3G, we will continue to provide voice and add data services-meeting the market demand by building out the networks with our existing infrastructures.