Compare & Contrast

Law Technology News (Volume 6, Issue 9, p. 36, col. 1)
September 1999

Cell Phones: Your Office Away from Your Office

by Wayne Spivak

CHANCES ARE, you already own a cell phone. With a market breadth of 70 million plus phones, with more than 30,000 new subscribers per day and the market growing at 25 percent per year, this seems a reasonable assumption. However, you may not know that not all cell phone service is alike.

Let's examine our definitions of cell phone service. For that, we have to understand cell phone technology. Cell phones connect to a network of low-power wireless transmitters set up to cover distinct geographical areas. These transmitters cover an area called a cell (thus, cell-phone). When a user moves from one area or cell to another, the call is handed off to the next cell, keeping your conversation seamless.

Analog	Digital Cellular	Digital PCS
Low calling capacity	Better Privacy - easily scrambled	Longer phone standby time
Limited spectrum	Larger spectrum	Two-way alphanumeric messages
No room for spectrum growth	Good fraud detection	Increased resistance to eavesdropping
Poor data communications	Backward compatibility	Fewer dropped calls
Minimal privacy		Data transmission for wireless e-mail, faxing, and Internet access
Inadequate fraud protection		Caller ID Backward compatibility

AMPS: Advanced Mobile Phone Service; another acronym for analog cellular radio. BTS: Base Transceiver Station; used to transmit radio frequency over the air interface. CDMA: Code Division Multiple Access; a form of digital cellular phone service that is a spread spectrum technology which assigns a code to all speech bits, sends scrambled transmission of the encoded speech over the air, and reassembles the speech to its original format. DAMPS: Digital Advanced Mobile Phone Service; a term for digital cellular radio in North America. DCS: Digital Cellular System. ESN: Electronic Serial Number; an identity signal that is sent from the mobile to the MSC during a brief registration transmission. ETDMA: Extended TDMA; developed to provide 15 times the capacity over analog systems by compressing quiet time. FCC: Federal Communications Commission; the government agency responsible for regulating telecommunications in the United States. FCCH: Frequency Control Channel. FDMA: Frequency Division Multiple Access; used to separate multiple transmissions over a finite frequency allocation; refers to the method of allocating a discrete amount of frequency bandwidth to each user to permit many simultaneous conversations. FM: Frequency Modulation; a modulation technique in which the carrier frequency is shifted by an amount proportional to the value of the modulating signal. FRA: Fixed Radio Access. GSM: Global System for Mobile communications; standard digital cellular phone service in Europe and Japan. To ensure interpretability between countries, standards address much of the network wireless infrastructure, including radio interfaces, switching, signaling, and intelligent networks. Hz: Hertz; a measurement of electromagnetic energy, equivalent to one "wave" or cycle per second. kHz: Kilohertz; thousands of hertz. MHz: Megahertz; millions of hertz. MS or MSU: Mobile Station Unit; (handset) MSC: Mobile Services Switching Center; a switch that provides services and coordination between mobile users in a network and external networks. MTSO: Mobile Telephone Switching Office; the central office for the mobile switch, which houses the field monitoring and relay stations for switching calls from cell sites to wireline central offices (PSTN). MTX: Mobile Telephone Exchange. NADC: North American Digital Cellular (also called United States Digital Cellular, or USDC); a Time Division Multiple Access (TDMA) system that provides three to six times the capacity of AMPS. NAMPS: Narrowband Advanced Mobile Phone Service; NAMPS was introduced as an interim solution to capacity problems; NAMPS provides three times the AMPS capacity to extend the usefulness of analog systems. PCS: Personal Communications Service; a lower-powered, higher-frequency competitive technology that incorporates wireline and wireless networks and provides personalized features. PSTN: Public Switched Telephone Network; a PSTN is made of local networks, the exchange area networks, and the long-haul network, interconnecting telephones and other communication devices on a worldwide basis. RF: Radio Frequency; electromagnetic waves operating between 10 kHz and 3 MHz propagated without guide (wire or cable) in free space. SIM: Subscriber Identity Module; a "smartcard," which is inserted into a mobile phone to get it going. SNSE: Supernode Size Enhanced. TDMA: Time Division Multiple Access; used to separate multiple conversation transmissions over a finite frequency allocation of through-the-air bandwidth; also used to allocate a discrete amount of frequency bandwidth to each user. To permit many simultaneous conversations, each caller is assigned a specific timeslot for transmission. Courtesy of the International Engineering Consortium - www.iec.org. Note: The information in the chart was obtained from manufacturers' Web sites and/or press releases. For more complete details please use the Reader Response card in this issue.

During the 1970s and 1980s, analog cell phone technology was developed and implemented. This technology permits cell phone communications, but also limits the number of cell phones that can be used in a given cell or geographical area. In the 90s, digital cell phone technology was initiated.

Today, where one analog cell phone conversation was available, three to six digital phone calls can be made. This 300 to 600 percent increase in capacity is one of the major reasons for the expansion in this market. However, newer technologies are gaining footholds, some capable of handling up to 15 calls per cell frequency (remember cell phones use radio waves). In addition, with each new technology, such as PCS (Personal Communication Services), added features are provided to the marketplace.

Today you have three choices for phone service and, depending on where you live in the country, you may not have all three. These choices are: Analog, Digital Cellular, and Digital PCS (see right).

There are two basic issues regarding cell phones: The phone itself, and the service offered by the carrier. Before you choose, be sure you have carefully assessed your anticipated use of the phone. For starters, consider your travel schedule and lifestyle before choosing a particular service or telephone.

Most carriers offer steep discounts on the phones -- and some even offer free phones -- if you sign up for one year or longer service agreements. Phones differ in style, feature and performance aspects, but here's a very important fact to keep in mind before you buy: Each phone system/carrier can only use certain phones. So here in New York, if you bought the digital StarTac by Motorola, you can use it with Bell Atlantic, but not AT&T.

The reasons for this are very interesting. There are three digital wireless platforms in the United States: CDMA, TDMA and GSM. CDMA is the newest technology, which is used by Bell Atlanic, Sprint PCS, AirTouch, PrimeCo, and GTE Wireless, among others.

AT&T and others use TDMA. OmniPoint and Western Wireless are two of the users of GSM. Each system is distinct, and they are not compatible with each other (from the digital PCS standpoint). Therefore, if your phone is not dual mode (digital PCS and analog), you may find yourself outside your calling area, with no cell phone service.

So before you buy, consider your travel routine. Ask your carrier specific questions about the extent of coverage to your usual venues. Lawyers who frequent small rural towns may find that a dual analog/digital carrier and phone will offer the most comprehensive coverage.

Security is also a factor: Prudent attorneys want cell phone calls to be as private as possible, and the new PCS systems do afford the best protection. However, a word to the wise; don't discuss matters over your cell phone that you wouldn't want to discuss in an open forum. These phone calls can still be intercepted -- remember Newt Gingrich's and Prince Charles' famous phone conversations!

Consider how you use your phone. Do you use the phone as a primary communications tool, only for emergencies or occasionally in the car? Today, many of the larger carriers offer "One-Rate" plans. These plans, for a set amount of money per month, not only give you a set amount of "free" minutes, but some of the plans also give you free long distance phone service. Again, depending on which plan, it may be related to a particular region (East Coast, West Coast) or the entire country. You can even get Canada for some additional dollars per month!

If you only make local or regional calls, your local carriers may have better plans for you. Remember, buy what you need, not what you want; otherwise you're more likely than not to be throwing dollars down the proverbial drain. If you don't call the other coast often, but do call up and down the coast you're on, then get a plan that maximizes your call pattern. It's as simple as dollars and sense!

Lost and Found

A final caveat: If your phone is stolen or lost, you may be in for sticker shock -- you probably won't qualify for promotional phone prices until your original service contract expires. A recent example: Replacing a stolen Sony CMM1300 would have cost its owner in excess of $300 from Bell Atlantic Mobile. The promotional price for the same phone was $69. (The answer: eBay, where a replacement phone was purchased for $122).

To protect your phone, tape your business card to it so that it can be returned to you if found; keep it zipped where it's not easily accessible to pickpockets; and consider insuring it if it's an expensive unit.

Then, there's always The Cellocate System: While doing research on this article, I came across this Orwellian product. The manufacturer claims it can locate any cell phone's position, for a variety of reasons and applications, including emergency 911 calls.

Wayne Spivak is president of Bellmore, N.Y.'s SBA* Consulting.