Roaming SIM
Encyclopedia
Roaming SIMs can be defined as mobile phone SIM cards that operate on more than one network within their home country. They currently have two main applications, least cost call routing for roaming
mobile calls and machine to machine.
Using a normal network locked SIM, travellers for instance, can use their own mobile phone (if it's enabled for roaming), in any country that has a roaming agreement with their home network. This manifests itself to most users when they receive a text message welcoming the traveller to a local network. However, once they return home their SIM will only work on the network with which they have a contract.
A roaming SIM however, also known as a global roaming SIM, will work with which ever network it can detect, at home or abroad.
Global roaming SIMs are very often combined with callback
technology, whereby the user dials a number in the normal way, but the call is intercepted by an application on the SIM card and turned from an outbound call to an inbound call which the user answers. This is to take advantage of the fact that inbound call charges are typically lower than outbound ones. Telecom North America
is one of the providers in the US using this technology.
Some providers achieve this automatic call interception and callback by encoding a program
onto the Sim card. For example BackChat Mobile in Australia utilises this method to intercept the call and send a network command to trigger the callback.
Increasingly, data services are being added to roaming SIm cards to reduce the cost of roaming data charges.
can be considered as an alternative.
Roaming
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...
mobile calls and machine to machine.
Using a normal network locked SIM, travellers for instance, can use their own mobile phone (if it's enabled for roaming), in any country that has a roaming agreement with their home network. This manifests itself to most users when they receive a text message welcoming the traveller to a local network. However, once they return home their SIM will only work on the network with which they have a contract.
A roaming SIM however, also known as a global roaming SIM, will work with which ever network it can detect, at home or abroad.
Roaming mobile calls
The use of roaming SIM cards in its most common form is in normal voice applications such as mobile phone calls. The common application of Roaming SIMs for voice is where mobile calls are automatically routed to, and made on a least cost network. This typically means that incoming calls are free, no matter which network a mobile user is on. This also means that a caller enjoys the cheapest cost when making a call, significantly reducing call costs, especially compared to normal network charges for International Roaming.Global roaming SIMs are very often combined with callback
Callback (telecommunications)
In telecommunications, a callback occurs when the originator of a call is immediately called back in a second call as a response.- International calling :...
technology, whereby the user dials a number in the normal way, but the call is intercepted by an application on the SIM card and turned from an outbound call to an inbound call which the user answers. This is to take advantage of the fact that inbound call charges are typically lower than outbound ones. Telecom North America
Telecom North America
Telecom North America Inc is an interexchange carrier licensed in all states of the USA and in all provinces of Canada. It was created on March 27, 2002, as the American subsidiary of 3U Telecom AG, a German telecom provider...
is one of the providers in the US using this technology.
Some providers achieve this automatic call interception and callback by encoding a program
SIM Application Toolkit
SIM Application Toolkit is a standard of the GSM system which enables the Subscriber Identity Module to initiate actions which can be used for various value-added services....
onto the Sim card. For example BackChat Mobile in Australia utilises this method to intercept the call and send a network command to trigger the callback.
Increasingly, data services are being added to roaming SIm cards to reduce the cost of roaming data charges.
Machine to machine
This technology is also used in a number of machine to machine applications where devices communicate with one another, for example in vehicle tracking systems, amongst other things, where complete network coverage is required but can only be achieved by using all the available networks. A roaming SIM, for example provided in the US by Neometry, can switch to any network, ensuring the best coverage. The cheap calls associated with Roaming SIMS are also paramount to enable certain machine to machine applications to be economically viable. It is anticipated that our exposure to Roaming SIMS, applied in a range of scenarios, will become prevalent as more and more applications for them are brought to market.Alternatives
For some applications (particularly where regular travel between two countries is the main purpose) a Dual SIMDual SIM
A dual SIM mobile phone is one which holds two SIM cards. Initially, dual-SIM adapters were made available to use in regular mobile phones to allow them to contain two SIMs, and to switch from one to the other as required. This combination is called a standby dual-SIM phone. The first Dual SIM...
can be considered as an alternative.