The use of SIM cards that support both private and public networks means that, when it’s turned on, the phone will automatically search for the preferred network, in this case the PMN network, in order to take advantage of the lowest call charges. If the PMN network is in range, the phone will go through a registration and authentication process. When this is completed successfully, the user of that phone can make and receive calls as normal.
This solution enables the mobile phone to move seamlessly between network coverage areas. “A phone that is registered to a PMN network will stay registered until it leaves the coverage area,” said Dean Parsons, Operations Director of Private Mobile Networks. “At this point, the SIM changes identity automatically and the phone moves to the macro network to make and receive calls. This change of networks is seamless and operates in exactly the same way as moving between service providers when automatic network selection is activated on a mobile phone,” added Parsons.
The phone will periodically check to see if a PMN network is in range. If one is found, it will be used, thereby reducing call charges.
The launch of the Private Mobile eXchange (PMX) product earlier this year, combined with the Spectrum now available from the latest Ofcom spectrum auction, allows companies to build a private GSM campus network. This network is able to carry GSM traffic between mobile phones used within the campus and from mobile phones across intra-site IP networks, without incurring mobile operator call charges. This latest development makes movement between the macro network and the private mobile network seamless and creates call cost saving opportunities, without any change being needed by the mobile network user. “A zero change user experience is what our customers have been asking for. That is what we can now deliver,” concluded Parsons.