Most network operators follow the same process when rolling out or expanding their network. This describes a typical example for outdoor cellsites to compare with the installation process for femtocells.
Complex radio planning tools are used to analyse the area to be covered. These import large databases of geographical information including the topology of the landscape including hills, buildings and vegetation. A simulation is run which identifies the best locations for cellsites to be added. Operators have two separate targets for their plans: coverage (i.e being able to use your phone in any part of the country, and including inside buildings, cars, moving trains etc) and capacity (i.e. ensuring there are enough traffic channels for everyone in an area to make and receive calls).
Once candidate cellsites have been identified, teams on the ground negotiate with potential landlords to take options on agreements for site rental and come back with usually a shortlist of nearby/alternative sites. One is selected, a site is built including installing power, equipment and transmission back to the operator’s network. Radio parameters are computed which include maximum transmission power, frequency, hopping (for 2G), coding sequence (for 3G), tilt (ie angle of the transmission antenna which can sometimes be set electronically) and a list of neighbour cellsites to handover to/from.
Project management systems will track the rollout or upgrade of each cellsite, and at each stage the status will be updated.
The transmission network connects the cellsite back into the core network of the operator, and the connection may be routed via leased lines, microwave links or high capacity SDH fibre owned by the operator (often a combination of all three). These are concentrated into an RNC (Radio Network Controller for 3G) or BSC (Base Station Controller for 2G). The transmission planners will allocate capacity from the cellsite to the central switching centre, including the port mappings for each input and output across every transmission hub. These are actively configured at the appropriate point in the cellsite rollout.
All basestations and RNCs are managed by a central Network Management System (NMS), which is used to configure and manage the equipment. Radio configuration parameters are downloaded into the basestations via the NMS. Operators often perform these configuration updates on a daily basis, overnight to ensure synchronised reconfiguration across the network, although more rapid online configuration is possible.
Fault management systems, such as IBM Tivoli Netcool or HP Temip, are used to capture, collate and analyse alarms and fault indications from the network equipment. They can correlate multiple alarms to filter out the root cause of a storm of error messages.
Performance management systems are used to monitor the capacity and overall throughput of the systems, and ensure maximum utilisation of the network. This information is used to identify where additional capacity or coverage is required, for example by tracking where large numbers of dropped calls or failed call attempts occur.
