Editor: David Crowe • Phone +1-403-289-6609 • Email [email protected] Vol. 9, No. 3 March, 2000 In This Issue... Question about national range of codes (see TIA/ SOC Codes EIA-136-123 for details). Question about SOC Codes p. 1 TIA/EIA-136 also allows for carrier spe- cific signaling using SOC code, although A reader asks us what a SOC Code is? Reader Eduardo Henriques Resende in What standards are they used by? Planejamento de Rede (Network Plan- it is not expected that this will be exten- And, how can one be obtained? ning) for Maxitel in Brazil asks: sively implemented. “I work for MAXITEL S.A., a cellu- SOC codes can be obtained by applica- Question about SID Codes . p. 1 lar operator in Brazil, and we need tion to: SID codes are equivalent to a radio some information about the parame- Editor, ANSI TIA/EIA-136 station’scall sign, and are fundamen- ter SOC (Service Operator Code). Committee TR45 tal to radio interfaces connected via Could you help us?” TIA/EIA-41. Unfortunately, it is not c/o TIA so easy to obtain a listing of them. The SOC (System Operator Code) is 2500 Wilson Blvd. Suite 300 defined for TDMA systems in IS-136 Arlington, VA 22201, USA International Update: SS7 and in the most recent ANSI versions in Global Title Routing........... p. 2 the TIA/EIA-136 series. The codes are Question about IS-807 (plus an addendum) provides assigned by TIA Standards Subcommit- guidelines on how global title can be tee TR-45.3 to carriers. Unlike the SID, SID Codes used (warts and all) to facilitate rout- the SOC code identifies a carrier, and can ing of TIA/EIA-41 messages across make intelligent roaming databases more Tim McCaffrey of Anritsu asks: international boundaries. compact as fewer entries are required. As SOC codes are 12 bits in length, there are “I would like to find a listing of all TIA TR-45.3 TDMA Digital 4,096 to choose from, although it may SIDs. For example: Sprint - 4188. Air Interface Standards ...... p. 5 only be the 2,048 international codes This will speed fault screening hand- sets” TR-45.3 is the TIA subcommittee (80016-FFF16) that are useful, as there are responsible for TMDA digital cellular some signaling problems with the An AM or FM radio station broadcasts a and PCS standards (known variously unique call sign, while a cellular or PCS as IS-136, ANSI-136, UWC/136 or base station (AMPS, TDMA or CDMA) D-AMPS). The complete list of stan- broadcasts a unique SID (System Identi- dards and projects that have been We Now Accept fier). SID codes are a global resource published by this subcommittee, or Diners Club which is allocated in blocks to countries. that are currently being developed is Individual SID codes are assigned We now accept Diners Club credit presented, organized by the major nationally. The ranges assigned to each cards for subscriptions, back issue phases of development. country are listed in TIA TSB-29 and at orders and other products. We con- www.ifast.org. The best resource for tinue to accept American Express, individual SID codes is probably the Visa and MasterCard, as well as Glossary CIBER manual, published by Cibernet checks, money orders and bank Corporation (phone: +1-202-785-0081), www.cnp-wireless.com/glossary.html transfers. Please choose the method although it may not have information of payment that is most convenient about carriers that do not participate in for you. Next Issue: April 3, 2000 CIBER billing record exchange. In these Cellular Networking Perspectives (issn 1195-3233) is published monthly by Cellular Networking Perspectives Ltd., 2636 Toronto Cresc. NW, Calgary AB, T2N 3W1, Canada. Contact Information: Phone: 1-800-633-5514 (+1-403-274-4749) Fax: +1-403-289-6658 Email: [email protected] Web: http://www.cnp-wireless.com/. Subscriptions: CDN$300 in Canada (incl. GST), US$300 in the USA and US$400 elsewhere. Payment by cheque, bank transfer, American Express, Diners Club, MasterCard or Visa. Delivery: Email or 1st class mail. Back Issues: Available individually for $35 in the US and Canada and $40 elsewhere, or in bulk at reduced rates. Discounts: Educational and small business discount: 25% off any order. Copies: Each subscriber is licensed to make up to 10 copies of each issue or back issue. Please call for rates to allow more copies. cases, national authorities (such as the but with significant difficulties. Systems Global Titles FCC in the United States) or individual outside the United States need to use carriers may have to be consulted. International Roaming MINs (IRMs), of A global title allows routing based on a numeric string, such as a calling card Some SID codes are never broadcast by which 50% have been taken, 10% having number, phone number (ITU-T Recom- a base station, but are only used in net- been allocated by IFAST mendation E.164) or IMSI (ITU-T work and billing messages for account- (www.ifast.org) within the past year. The E.212). The original node places a global ing purposes (e.g. to identify markets 15 digit IMSI provides a much greater title in the Called Party Address field within a system identified by a single number of unique identifiers. Further, (CdPA) of the SS7 SCCP layer, and each SID). These codes, known as BIDs (Bill- they can be allocated independently by STP resolves the address into either the ing IDs) are assigned upon request by each country, without need for interna- point code address of the next STP, or the Cibernet Corporation. tional coordination, unless a country needs a new Mobile Country Code. IMSI actual destination address. A global title Air interface standards treat the SID as a is universal in GSM, and is now an may also be included in the Calling Party 15 bit number (0..32,767). These SID option in TDMA (TIA/EIA-136) and Address field (CgPA) for routing of codes are in relatively short supply due CDMA (TIA/EIA-95) digital standards replies. Global titles can be used for to the inefficient allocation scheme that as well as the TIA/EIA-41 standard international routing as long as: was originally used. Since network and (through IS-751). It is not available in • A compatible global title exists in billing SID codes are transmitted and any analog (AMPS) standards. IMSI has both SS7 networks, and stored as 16 bits numbers, there is no not yet been widely implemented in sys- • International gateways support the shortage of these codes (i.e. there are tems other than GSM, although this is global title. 32,767 codes that can be used on the net- expected to change in 2000. work, but not on the radio interface). IS-807, a recently published TIA stan- dard, has provided guidelines for inter- International Signaling national global title routing in TIA/ International Update: EIA-41 networks, although a recent IMSI helps systems identify interna- change of direction has required the pub- SS7 Global Title tional roamers, and their home systems, lication of an addendum to the original but it cannot solve the problem of com- Routing recommendations. IS-807 is not a com- municating with the home system over plete solution, however, as it does not the SS7 signaling network (although it is International roaming is definitely one of identify a full set of global titles for use part of the solution). Currently, most the weaknesses of cellular and PCS sys- outside the ANSI SS7 network. Figure 1 international roaming solutions simply tems connected by the TIA/EIA-41 illustrates the international routing of a extend the ANSI SS7 signaling network (“ANSI-41”) standard for inter-system TIA/EIA-41 operation assuming that all into countries outside North America operations, and one of the strengths of the pieces are in place. GSM. This reflects the birthplaces of the instead of using native SS7 protocols. two families of standards. GSM was cre- This is frowned upon by North American Choice of Global Titles ated specifically to facilitate a seamless SS7 standards organizations (e.g. T1S1) pan-European cellular system, while and resource assignment authorities Not all TIA/EIA-41 signaling messages AMPS was designed for use solely because it could lead to wireless systems can use the same type of global title and, within the United States. However, TIA/ in other countries exhausting a North in some cases there are a variety of EIA-41 is growing into an international American resource. It is also undesirable choices for the global title for an individ- standard, with international roaming for other countries, because it means that ual signaling message. Identifying a sin- becoming a necessity, not a luxury. It is they have to implement two parallel SS7 gle choice simplifies network design by not that many years since roaming within networks, and their access to the ANSI limiting the scope of modifications to the US was considered a luxury, yet it is network could be terminated at short network elements that may have to orig- now considered essential by many wire- notice. inate, route or respond to TIA/EIA-41 less consumers. The lowest level SS7 address is the point messages. code, but it definitely cannot be used for In the case of a mobile registration, the International Mobile international roaming. Not only is the choice is relatively simple, because the address space re-used in each country only identifier available is the one that Identifiers with a distinct SS7 network, but the sizes the mobile transmitted over the radio One of the challenges with international of point codes varies from 14 bits in interface.