System identification number: Difference between revisions

Revision as of 03:57, 2 June 2014

Revision as of 04:42, 17 February 2020

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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.

[[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, however. manyMany countries do not use all of their allocated codes, sohence the majority of codes are not usedunused.

SIDs are assigned to every carrier (e.g., Verizon, Sprint, Alltel) by national regulators or [[IFAST]]. SIDs are programmed into the phone when you purchase thempurchased. 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).

==How SIDs work==