System identification number: Difference between revisions

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A '''system identification number''' ('''SID''') is broadcast by one or more [[base station]]s to identify a cellular network in a certain area (usually contiguous). It is globally unique within [[Advanced Mobile Phone System|AMPS]], [[Digital AMPS|TDMA]] or [[CDMA]] networks (the first two systems are essentially obsolete). This number sometimes has conflicts (see [[IFAST]]).

==SID Codescodes==

'''System Identification Number''' can represented by the [[acronym]] '''SID'''. It is a Global number to identify [[Base station|base stations]] for [[AMPS]], [[Time division multiple access|TDMA]] or [[CDMA]] networks. This number sometimes has conflicts (see [[IFAST]]).

These codes are broadcast as 15 bit values but transmitted as 16 bits by core network protocols. They can be listed within a [[wireless device]] to show preference for one network over another. The additional bit in core network protocols allows the range of codes above 32,767 to be used for internal purposes, such as segregating billing records within a large area identified by a single broadcast SID.

==SID Codes==

These codes are 15/16 bit values and can be listed within a [[Wireless Device]] to show preference for one network over another.

TIA TR-45.2 assigned ranges to every country in the [[1980]]'s and national regulators assigned individual numbers. [[IFAST]] took over in [[1997]].

This number space is 90% utilized, however many countries do not use all of their allocated codes.

[[Telecommunications Industry Association]] committee TR-45.2 assigned ranges to every country extant in the 1980s and national regulators assigned individual numbers. [[IFAST]] took over in 1997. This number space is 90% utilized for country ranges. Many countries do not use all of their allocated codes, hence the majority of codes are unused.

SID is assigned by [[IFAST]] to every carrier(e.g., Verizon, sprint). SID is programmed into the phone when you purchase/buy a plan.

SIDs are assigned to every carrier (e.g., Verizon, Sprint, Alltel) by national regulators or [[IFAST]]. SIDs are programmed into the phone when purchased. A phone will maintain a list of "preferred" systems identified by their SID code. The SID may also modify some signaling messages that are transmitted by mobiles (e.g. reducing the amount of information transmitted by "home" mobiles).

When the phone is powered ON, it listens to SID. If it receives an SID, it compares with the one that is stored in the phone. You have service if there is a match. Else you are "roaming"

==How SIDs work==

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When the phone is turned on, it listens for a signal. If it receives a signal, it looks at the SID carried by the signal, and compares it with the one that is stored in the phone. Originally, in analog systems, the mobile would turn on the [[roaming]] indicator if the SID was not the single value stored in the phone.

[[Category:wireless communications]]

[[Category:identifiers]]

With CDMA systems the [[Preferred Roaming List]] (PRL) is responsible for determining which areas a mobile can roam into. [[Base station]]s may also broadcast an [[List of mobile country codes|MCC]] and [[Mobile Network Code|MNC]] which can also be used by the PRL.

==External links==

*[http://www.mountainwireless.com/sid/ Mountain Wireless SID database]

*[http://ifast.org/SID.htm IFAST SID Information]

[[Category:Mobile phone standards]]

[[Category:identifiersIdentifiers]]