Digital Airplay

Although cellular providers say that analog is a timeless classic, digital networks are becoming more mainstream. An expanded repertoire is great for your customers, but from a business perspective, is it really cost-effective to keep analog running?

Stuart Rosenfield, Ericsson marketing manager, finds endless comparisons between the cellular and music industries.

"For example," he said, "CD-ROMs are a lot cheaper to make than LPs, and you can get more on a CD-ROM than you can an LP, so the music industry wants consumers to buy CD-ROMs. Likewise, digital is cheaper to produce than analog because, as far as voice patterns go, more voice paths can fit on a digital channel than an analog channel."

Elliott Hamilton, The Strategis Group director of North America telecom, agreed that more operational and technical costs are associated with maintaining two networks.

"In the most desirable world, once you get the digital network out, you would shut down your analog because at some point it's not efficient to divide up your spectrum," he said. "As the number of digital subscribers becomes higher while you are still adding analog customers, you are definitely getting a big reduction in capacity by having two segments of spectrum."

With more than 57 million users on analog, however, the network isn't going to disappear any time soon, said Claudio Vergara, Nortel senior manager of CDMA network engineering. As a cellular operator, the last thing you are about to do is tell a large base of analog customers that you're cutting them off.

"Even though there may eventually come a time that almost everything will be digital, operators are going to have to manage dual-mode networks in the meantime," Vergara said. "There is no getting around it."

The First Movement Some carriers have had lots of practice setting up digital networks in various markets. They have learned from their own mistakes, and they have advice to give. To overcome the capacity problems that Hamilton mentioned, Bell Atlantic Mobile employed an analog overbuild strategy when it rolled out its digital network in January 1997, said Cory Streeter, staff director of CDMA. Doing so maintained its quality of service to analog customers.

"We increased our build plan and probably doubled the number of cell sites that we normally would build in a year to increase the capacity of the analog system," Streeter said. "That allowed us to free up spectrum for our first CDMA carriers, and we're hoping that having done that, it should be enough of an analog build-out to allow us an easy transition to the second CDMA carrier, the third and so on."

When Bell Atlantic Mobile first ran digital trials in Trenton, NJ, it created a firewall to protect the two systems by deploying digital equipment in or next to existing equipment, said Gene Oliva, member of technical staff. A year later, the company now runs digital in six major East Coast markets. Taking the first block of spectrum and moving it to digital before it had any digital traffic was the company's biggest challenge, Oliva said. Now that Bell Atlantic Mobile has so much traffic on the digital network, it is starting to offload its analog system. Because it has been through the process once already, he said, it should be easier for the company to make the next transition.

Streeter said running two networks comes down to careful planning.

"We really have to balance our spectrum between analog and CDMA, and as we progress with our CDMA penetration, we're going to need to move more and more of our spectrum to CDMA," he said. "CDMA offers us higher capacity than analog, so when we make that tradeoff, we increase the capacity of our system, but it's definitely a delicate balancing act."

A Harmonious Segue As you add digital service and begin implementing CDMA, TDMA or GSM technology, even more obstacles may come up. Rosenfield noted that if you have older equipment, you must overcome other challenges when it comes to digital penetration. First, you must be sure that your RF planning is tight because digital is much more precise than analog. You also will need to make some changes to the radio infrastructure, whether it is software driven or hardware driven, to support digital.

"A lot of it depends on what revision of hardware you have," Rosenfield said. "Primarily, you have to add radios in the older equipment, but with the new radio base stations, it's more of a software change. Generally, if the equipment is more than four years old, you would put in digital transceivers or replace the analog transceivers."

AirTouch Communications faced a potential problem when it made a corporate decision to use CDMA technology because it had an Ericsson analog network, and Ericsson does not offer CDMA technology. Nortel helped the company solve the problem by placing a CDMA overlay on the existing Ericsson analog network throughout the entire metro Detroit area, Vergara said.

"This overlay gives the cellular operating company a choice to not always go with their current vendor's portfolio," he said. "It can actually go with another vendor and still give the end user a transparent digital cellular network."

Nortel worked to implement interoperability and feature transparency between the two vendors, and AirTouch has had so much success with the overlay network that it is expanding its current coverage in the Detroit area. Nortel has released other products that can help manage multiple networks, too. Nortel's MTX Data Server features a Hewlett-Packard server-based system that addresses several needs. It manages billing records through the switch, so it can do multipoint distribution of billing for fraud systems and rental billing, and it also collects call-detail records and stores them in a database. Some carriers use the program for marketing studies or customer care, said Bill Bradee, who is responsible for Nortel's MTX Data Server product line management.

Another new component to the MTX Data Server is a fault- and performance-management system, which receives fault-performance data from Nortel's switches and provides various performance reports related to the operation of the switch.

Adept is another tool in Nortel's operations administration and maintenance portfolio. It helps operators who are undergoing rapid expansion to plan for growth because it can determine if the system is in danger of exceeding its engineered capacity. You can perform calculations to see how the systems react when you re-arrange the components in your network. There is a version for the AMPS/TDMA networks and another for AMPS/CDMA.

Nortel's RF Optimizer is more concerned with analyzing performance on the radio side of the equipment. It takes drive-test data, crunches it and gives you a graphical display of call events. The analysis provided (by the RF Optimizer) will allow the operator to make the necessary adjustments to improve network performance.

A variety of dual-mode radio base stations also is available to ease the transition between analog and digital. Lucent Technologies' Series II Cell Site is based on modular architecture, said Sam Gronner, media relations manager. In addition to analog, the Series II platform supports digital technologies, including TDMA, CDMA, PCS at 2GHz and CDPD.

"Plug-in radio modules enable you to add new features as technology changes or add capacity as customer-service needs increase," he said. "Series II cell sites are digital-ready so that when the carrier is ready to go digital, it is just a matter of changing out certain packs to change sectors that want to go digital. TDMA radios can be installed in the same frame as analog radios to achieve digital capability and features on an existing analog network. To migrate to CDMA technology, you will plug CDMA channel units into a CDMA growth frame."

Lucent also announced a new architecture that will evolve digital technology into the next generation, Gronner added.

Similarly, Ericsson's solution is the RBS 884 Macro radio base-station system. It is equipped with multimode and multifunctional transceivers. On command, the same hardware module can be used as an analog transceiver, a digital transceiver, a signal-strength-measurement module or a location-verification module.

Nortel offers its DualMode Radio, a DSP-based software controlled radio that changes the personality of the radio from analog to TDMA digital as well as downloads CDPD software, said Mark Buford, senior manager of industry relations.

"If the radio is supporting analog traffic and the calls are kind of slow, and the network needs more digital capacity for a given call, then the network changes that radio to a digital radio and makes it available to make or receive calls," he said. "If you have a network where you have separate analog and digital, you might have to install a certain number of each radio based on what your peak traffic capacity will be, which means at your non-peak times, you will have excess capacity. With Nortel's DualMode Radio, you don't have to do that because you have radios that can be analog or digital, depending on what you need. The net effect is that you need less radios for the same coverage."

Modular equipment does make it easier to manage both networks, no matter how long you keep them running. Ken Woo, external communications manager at AT&T Wireless, which uses both Lucent and Ericsson infrastructure equipment, said when analog subscribers request a change to digital, it's just a matter of switching out analog radios for digital ones.

"All of our cell sites are modular, so if we get 50% off one particular site, it's just a matter of pulling out 50% of the analog radios and dropping 50% of the digital radios in," he explained. "It's like having a dresser drawer. You have one drawer for socks and another one for sweatshirts, and you want more socks than sweatshirts. It's just a matter of taking the sweatshirts out and replacing them with socks."

AT&T has digital up and running in 121 MSAs and nine BTAs.

Similarly, GTE Wireless, which has introduced digital service in 17 markets since 1996, finds maintaining both networks fairly easy with the dual-mode radio base station.

"Our digital network is already integrated into a lot of the parts of our architecture," said John McLean, vice president of technology. "It is run basically on the same stuff as our analog, with the same switching and networking infrastructure."

Signing Off or Continuous Play? The technology is available to help you, but how long will you have to keep two networks running simultaneously? Rosenfield returned to his music analogy to explain why he believes an end to analog is in sight. When the music industry first introduced compact discs, he said, consumers were hesitant to jump right into the new technology, especially since they had invested so much in their LP collections. Even after they bought CD players, they still didn't exchange their LPs for CDs all at once; most replaced them one by one. Rosenfield predicts that analog subscribers, like music fans who gradually embraced compact discs, eventually will switch over to digital.

"There are a lot of subscribers who use analog right now because they don't know they need voice mail, they don't know they need a lot of things, but they will as they become more sophisticated users," he said. "A lot of the cellular users of today are in their mid- to late 40s, but the wireless users of tomorrow are now in their teens and in elementary school, and they are going to demand digital-type features. My 9-year-old complains because his Internet link isn't fast enough, but it would be fine for my 65-year-old parent. So is my son going to go for the analog? Probably not. He is going to be a digital subscriber from day one."

Rosenfield pointed out that more active users of cellular already are choosing digital because if they are on the phone for 200 to 300 minutes a month, the $150 investment for a phone is not a bad deal. He predicted that when digital phones cost as little as analog phones do, it eventually will kill analog, or at least reduce its sales. New features such as prepaid phones or calling party pays will help remove some of the barriers that low-end users have, he said. He added that the death of analog is years away, unless cellular operators make subscribers a sweetheart deal or make a corporate decision not to sell analog anymore.

He conceded that although eventually there will be no analog sales, there still will be a significant number of analog subscribers to support until it becomes financially attractive for the dual-mode operators to go to one mode.

"There's a lot of analog out there, and until that market goes away, it doesn't make sense to get rid of analog. Now, it does make sense to promote digital and settle for analog (customers)," he said.

That's what many carriers have begun to do, said Andrea Linskey, Bell Atlantic Mobile spokesperson. It's up to you, the carrier, to let consumers know the features that go along with digital technology and how they differ from analog, she said. Cellular providers have begun producing commercials that highlight these functions, so as consumers become more educated about how they may help with their business needs, they will adopt them. However, she added, there always will be customers who keep their phones in their glove boxes for occasional use. In her opinion, analog is likely to remain their choice.

Hamilton predicted that the analog network won't disappear yet for roaming reasons, as well. In order for you to get rid of analog, he said, you would have to have an almost completely digital network. But McLean added that even if carriers have digital in all of their U.S. markets, analog still would have a rather robust presence.

"You have three digital standards in the PCS arena with GSM, TDMA and CDMA, and the only common base they have to fall back on is analog," he said. "Take, for instance, a city like Dallas, where the two owners of the licenses both deal with TDMA. If you were to take away analog in that market, you would have no way for CDMA subscribers to roam into that market unless handset manufacturers provided dual technology for both CDMA and TDMA, or unless everyone moved to some future common technology, as opposed to the five different technologies we have today."

The bottom line, Rosenfield said, is that cellular carriers still offer analog because subscribers still demand it, yet customers will demand it as long as it's available.

"It's a Catch-22," he said. "But it is like buying a new car. At some point, people will discard their old cars, and at some point, the analog will go away because operators' cost vs. network upkeep will change the balance, and it will behoove the analog operators to transfer over."

Until that day, cellular providers must maintain both networks without sacrificing the quality of either. Vendors are listening, and they will continue to create technology to help you juggle multiple networks. Regardless of whether or not analog goes the way of the LP, it's important to take a good, hard took at the services and technology available to you, just as your own customers would.