System Identification Number
Encyclopedia
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 AMPS
, TDMA
or CDMA networks (the first two systems are essentially obsolete). This number sometimes has conflicts (see IFAST
).
TIA 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 many countries do not use all of their allocated codes so the majority of codes are not used.
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 them. 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).
indicator if the SID was not the single value stored in the phone.
However, with CDMA systems the Preferred Roaming List (PRL)
(PRL) is responsible for determining which areas a mobile can roam into. Base stations
may also broadcast an MCC and MNC
which can also be used by the PRL.
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
s to identify a cellular network in a certain area (usually contiguous). It is globally unique within AMPS
Advanced Mobile Phone System
Advanced Mobile Phone System was an analog mobile phone system standard developed by Bell Labs, and officially introduced in the Americas in 1983, Israel in 1986, and Australia in 1987. It was the primary analog mobile phone system in North America through the 1980s and into the 2000s...
, TDMA
Digital AMPS
IS-54 and IS-136 are second-generation mobile phone systems, known as Digital AMPS . It was once prevalent throughout the Americas, particularly in the United States and Canada. D-AMPS is considered end-of-life, and existing networks have mostly been replaced by GSM/GPRS or CDMA2000...
or CDMA networks (the first two systems are essentially obsolete). This number sometimes has conflicts (see IFAST
IFAST
iFAST Corporation Pte Ltd is a Singapore-based company with subsidiaries in Malaysia, Hong Kong and India....
).
SID Codes
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.TIA TR-45.2 assigned ranges to every country extant in the 1980s and national regulators assigned individual numbers. IFAST
IFAST
iFAST Corporation Pte Ltd is a Singapore-based company with subsidiaries in Malaysia, Hong Kong and India....
took over in 1997. This number space is 90% utilized for country ranges, however many countries do not use all of their allocated codes so the majority of codes are not used.
SIDs are assigned to every carrier (e.g., Verizon, Sprint, Alltel) by national regulators or IFAST
IFAST
iFAST Corporation Pte Ltd is a Singapore-based company with subsidiaries in Malaysia, Hong Kong and India....
. SIDs are programmed into the phone when you purchase them. 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
When the phone is turned on, it listens for a signal. If it receives a signal, it looks at the SID (being carried by the signal), and compares it with the one that is stored in the phone. Originally, in analog systems, the mobile would simply turn on the roamingRoaming
In wireless telecommunications, roaming is a general term referring to the extension of connectivity service in a location that is different from the home location where the service was registered. Roaming ensures that the wireless device is kept connected to the network, without losing the...
indicator if the SID was not the single value stored in the phone.
However, with CDMA systems the Preferred Roaming List (PRL)
Preferred Roaming List
The Preferred Roaming List is a database residing in a wireless device, such as a cellphone, that contains information used during the system selection and acquisition process. In the case of RUIM-based CDMA devices, the PRL resides on the RUIM...
(PRL) is responsible for determining which areas a mobile can roam into. Base stations
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
may also broadcast an MCC and MNC
Mobile Network Code
A Mobile Network Code is used in combination with a Mobile Country Code to uniquely identify a mobile phone operator/carrier using the GSM/LTE, CDMA, iDEN, TETRA and UMTS public land mobile networks and some satellite mobile networks...
which can also be used by the PRL.