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Mobile Infrastructure Sharing—Types of Network Sharing

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Operators may face challenges in implementinga shared RAN network formed from existingnetworks, as their architectures have evolvedindependently to date. For example, there may becomplications around inter-working of equipmentpurchased from different vendors and operational

procedures and control mechanisms.

3.4 Core network sharing

At a basic level, the core network consists of:

• Core transmission ring.

• Switching centre (with the home location register(HLR)).

• Billing platform.

• Value Added Systems (VAS) that representlogical entities and may also form part of the corenetwork.

The core network may be shared at one of two basiclevels, namely the:

• Transmission ring.

• Core network logical entities.

3.4.1 Transmission ring sharing

Where an operator has spare capacity on its corering network, it may be feasible to share this withanother operator. The situation may be particularlyattractive to new entrants who are lacking in timeor resources (or desire) to build their own ring.They may therefore purchase capacity, often in the

form of leased lines, from established operators.Fixed network operators, such as British Telecomand Cable & Wireless, which sell capacity ontheir network on a wholesale basis often provideoperators with an interim mechanism to roll outa network quickly while they make arrangementsto implement their own architecture. However, if both companies use the same joint transmission andswitching core then their services will become morealigned as they will have the same infrastructurecapabilities. Any service, function or process thatone operator implements can be replicated by theother as they have the same infrastructure capability.

3.4.2 Core network logical entity sharing

Core network logical entity sharing represents amuch deeper form of sharing infrastructure andrefers to permitting a partner operator access tocertain or all parts of the core network. This could beimplemented to varying levels depending on which

platforms operators wish to share. A simple examplemay be sharing the equipment identity register(EIR) function, which on its own may be expensive but as a pooled resource between operators becomesmore attractive.

The benets for sharing core network elements arenot as clearly dened as those for sharing the accessnetwork. It is conceivable that there may be somecost reductions in operations and maintenance butthe scale and practicality of these remains uncertain.Operators’ focus for network sharing to date hasconcentrated on elements in the access networksince the cost savings in this area are typically moresignicant and better understood.