Billing Data in Real Time

Billing in real time ... billing in gory detail ... billing for enhanced services ... billing wireless data transmissions ... traffic statistics ... customer-care statistics ... marketing information ... fraud monitoring. If you were promised a standard with all of those capabilities, wouldn't you leap at the opportunity to use it? Yet, such a standard exists, and carriers have been slow to adopt it. TIA interim-standard IS-124 first was published in 1993, but as it moves into its third revision, its future still is unclear.

Real-time billing is desirable for a number of reasons. New services are made possible, or at least more efficient and leak-proof, through real-time billing, including prepaid calling, calling party pays, rental phones and providing call charge information to wireless subscribers.

Perhaps more important is reducing the time between when a call is made and when it appears on a customer bill. During this time, either the serving carrier or the home carrier is financing the caller. The sooner a billing record can be delivered from the carrier that served the roamer to the home carrier, the sooner the serving carrier receives payment.

Furthermore, the longer the delay between making a call and receiving a bill, the more likely a caller is to forget that he even made the call, which means he also is more likely to challenge the charge.

Billing standards are required in wireless, largely because of roamers. When someone else's customers can access your system, you must have some way to get information back to their home systems so that you do not have to bill them directly. Also, enough information has to be collected to ensure that the home carriers send your portion of the roaming revenue they collect back to you.

Currently the dominant billing standard is the CIBER record, which is fundamentally a magnetic tape format, although it is transferred over networks as well. CIBER formats date back to a simpler era, when all record structures were fixed in length, and all data was in text format. The record content is focused entirely on billing, and the records only coincidentally contain information that can be used for other purposes.

Flexibility IS-124 (soon to be renamed ANSI standard TIA/EIA-124 Revision B) is, by contrast, a modern standard. All information is in hierarchical format, with variable length records and fields containing a large variety of binary encoded information -- some mandatory, some optional.

Because of this flexibility, IS-124 records can be customized to satisfy one purpose or many simultaneous purposes. This flexibility comes at a price, however. Information cannot be recognized simply by its position in a rigidly structured record. Each piece of information must be identified, and the pieces of the hierarchical list of sub-records must be linked together, often in both directions. This makes the records significantly larger, increases network throughput requirements, multiplies computer processing requirements, and increases the cost and complexity of software development.

The flexibility of IS-124 also introduces a compatibility problem. Unless the entire standard is implemented, which would result in whale-size records with a similar proportion of fat, it is necessary to develop agreed subsets of IS-124 for different applications. Cibernet initiated industry meetings for this purpose. First came a non-signaling data protocol for fraud (NSDPF), which allowed the exchange of call-detail records in IS-124 format for post-call fraud monitoring. Although authentication has removed the usefulness of some IS-124-based fraud applications, burgeoning interest in subscription fraud has made other applications even more critical. According to Dubi Silverstein of Systems/Link, NSDPF (and its close cousin DMH-Lite) is being used to reduce fraud by several major U.S. and Canadian wireless carriers, including 360 Degrees, AirTouch, Alltel, Ameritech, Bell Mobility, Bell-South, GTE Wireless, PrimeCo, SNET and Unitel.

Following NSDPF, the Cibernet-led group initiated the development of a non-signaling data protocol for billing and settlement (NSDPB&S). This recently completed effort actually was more than the development of a subset. It identified some weaknesses in Revision 0 of IS-124, and corrections became an important input to the development of Revision A by TIA standards subcommittee TR-45.2.

Further corrections to IS-124 are being incorporated in TIA/EIA-124 Revision B, which currently is in the ballot process. Major players in this process include Metapath (editor for IS-124 Rev. A), Systems/Link (editor for TIA/EIA-124 Rev. B), EDS (source of many technical corrections), Ericsson and consultant John Willse (TIA TR-45.2 Working Group IV chairman). Originally, McCaw (now AT&T Wireless Services) and Synacom contributed significantly to the development of Revision 0.

One More River to Cross One more hurdle to IS-124 implementation is the lack of a single, standardized transport protocol. Although many telecommunications interfaces allow multiple transport protocols, generally there is a single lowest common denominator. PSTN interconnection, for example, uses MF tones as the basic transport protocol, and IS-41 used X.25 level 2. This allows a transition to a protocol with greater performance and capabilities (which, for both PSTN interconnect and IS-41 is SS7), without losing compatibility with older systems. CIBER records used 9-track magnetic tape as the original transport medium and have since migrated to other tape formats and even electronic file-transfer of records.

However, there certainly are no billing houses that still would not accept 9-track tapes today. Without a single basic standard transport protocol, those that implement IS-124 are forced to develop agreements ahead of time to ensure compatibility. Should it be TCP/IP, frame relay or ATM? This is especially difficult for prospective equipment vendors that do not know for which network protocols they should design.

Real-time billing and faster settlement processing eventually will herd the industry toward IS-124 implementation, but it still will take some time because the on-line exchange of CIBER records is a viable option today. Although CIBER is much less flexible, it is available and is more compatible with much of the existing billing infrastructure.

Gradually, as all the pieces come together, as IS-124 equipment and services become available, and as the demands for real-time billing increase, carriers will commit to IS-124. A recent NACN trial involving EDS, Metapath and Vertel has, according to Metapath's Peter Larsen, shown that the pieces of the puzzle can be put together; although, it will be awhile before fully commercial applications are available. Ironically, interest is growing in Europe regarding IS-124 because it is compatible with GSM and provides considerably more flexibility than GSM's current TAP billing standard.