A Refocus on Standards

A few short years ago -- when PCS was young -- it seemed that wireless standards had faded in importance. The plan apparently was to put together a nationwide presence that would avoid the need for roaming and multitech-- nology phones. Some dreamed of a single-technology system in which the lack of standards would not be a detriment but rather a way of distinguishing their nationwide systems from the competition and a way to reduce churn.

Things have not turned out this way, and new carriers are beginning to refocus on standards. After all, even a nationwide carrier needs international roaming agreements, and with the enormous number of licensed areas in the United States, it is unlikely that any one carrier will ever cover the entire country. Taking into consideration the concepts of franchising and common branding and the need for common communication channels between carriers, the need for standards becomes even more obvious. And who's to say whether agreements between carriers always will be drawn within technological barriers?

Standards are important even within your operation as a single wireless carrier. You most likely have multiple suppliers of infrastructure equipment, and the most cost-effective way to facilitate interoperability is through standards. Whether it is communication between mobile switching centers (MSCs), between an MSC and a home location register, or between an MSC and a base station, a protocol is required, and a standardized protocol promises significant benefits.

Network Interconnection Radio interface standards are no longer the most important standards in wireless. As multimode phones become more practical, and roaming becomes more im portant, the network interconnection is of paramount importance. Without a network to carry information from the current serving system to the home system, you cannot support the fancy features of new air interfaces. Fortunately, in the arena of network interfaces, only two major competitors exist: GSM MAP and IS-41.

The fundamental difference between GSM MAP and IS-41 means that a larger gulf exists between GSM and IS-136 TDMA systems in the United States than between IS-136 and CDMA -- even though GSM and IS-136 both use TDMA technology. Only a basic level of compatibility is possible between systems that are connected to a GSM network and those connected to an IS-41 network. This translates into limited capabilities for GSM/AMPS phones that are developed to extend the reach of U.S. GSM-based PCS systems.

For example, while mobiles can hand off from IS-136 TDMA or IS-95 CDMA modes in either the PCS or cellular bands to AMPS in the cellular band, GSM phones are not able to hand off to any other technology. This is because of the lack of interoperability between GSM MAP and IS-41. Because the methods of intersystem handoff are different, the industry is unlikely to overcome this limitation. Similar barriers apply to feature control, short message service and authentication.

The need for standards in wireless is real, but a larger need is for standards between wireless systems and wireline systems. A good example is the calling party pays (CPP) feature. CPP operates under a simple philosophy ("You call, you pay.") and is quite easy to implement in many countries. But, in the United States, because of the vast number of carriers of all types, this feature must overcome significant hurdles. This will require standardization and perhaps even regulatory intervention to ensure that all carriers can communicate for the benefit of their subscribers.

The Cellular Telecommunications Industry Association now is developing a CPP service description in an attempt to stimulate the standardization that must occur. It is too early to define exactly what standards will be required, but they certainly will tie together systems that today operate completely independently.

Think about the case of someone calling a CPP mobile phone from a pay phone. Currently, "smart" pay phones can determine the cost of a call by looking at the dialed digits. If a local NPA-NXX is dialed, the call might cost 25 cents no matter how long it takes. If another North American number is dialed, the call might be charged at 25 cents a minute, with other rates applying to international calls. But a CPP local call perhaps should be rated at 25 cents a minute, passing the cost of airtime back to the caller. How can the pay phone possibly know about this charge? How can it reimburse the carrier? The answer is that it cannot, unless it has the ability to communicate with the local wireline switch to which it is connected as well as the home system of the CPP subscriber.

Local number portability (LNP) is another service that will require enormous cooperation between carriers. Moving phone numbers from one carrier to another requires a method for communicating the service order, along with access to a central database to control call routing. The fact that LNP is a government-imposed mandate while CPP is an industry-desired feature is irrelevant. Both require the ability to communicate in new ways.

CPP and LNP are just two examples of emerging services that will require unprecedented cooperation among diverse carriers -- not just cooperation, but often instantaneous cooperation, which will require a real-time computer protocol. With the mind-boggling number of existing and future carriers in the United States, the need for standards only can grow. Other countries trying to increase competition in wireline and wireless telecommunications also will develop a similarly insatiable appetite for standards.

Lawfully Authorized Electronic Surveillance (LAES) The CALEA "wireless wiretap" legislation first was balloted as SP-3580. After this ballot was rejected on a split vote (industry in favor, law enforcement against), the legislation was simultaneously re-balloted as SP-3580-A (ANSI ballot), PN-4116 (TIA interim standard) and as a T1 (ATIS) trial-use standard. The ANSI ballot may have to be abandoned because of massive law enforcement opposition (almost 200 "no" votes). Both the TIA and T1 ballots succeeded, with the industry in favor and law enforcement unable to vote.

Wireless Number Portability (WNP) Wireless number portability is being developed in two phases. PN-3980 will support the number portability database query to allow mobile-to- (ported) land calls. This document has been approved for publication. A second phase, under development, will allow roaming by ported wireless subscribers.

Enhanced Wireless Emergency Services (E-911) PN-3581, to be published as J-STD-034 (joint TIA/ATIS standard), supports the first phase of the FCC's E-911 Report & Order, including approximate location (cell/sector), mobile identification and callback. A second phase, named project PN-3890, will provide location information with 125-meter accuracy, supporting Phase II of the FCC R&O.

Calling Party Pays (CPP) No U. S. standards exist for calling party pays. The Cellular Telecommunications Industry Association has initiated an effort to develop a service description to be forwarded to standards organizations this year. The FCC has published a Notice of Inquiry.