The deployments of Long-term Evolution (LTE) Evolved Packet Core (EPC), Voice over LTE (VoLTE), and IP Multimedia Subsystem (IMS) networks use the Diameter protocol for control plane signaling, as opposed to the legacy Signaling System 7 (SS7), which is mainly associated with 2G and 3G networks, but is still the main signaling protocol used in many markets today. SS7 will not go away until 2G and 3G completely stop operating, and ABI Research believes that SS7 will need support for at least another 10 to 20 years.
All 4G infrastructure vendors support Diameter in their LTE products, as Diameter is required for 4G LTE. Diameter routing solutions are provided by many original equipment manufacturer (OEM) vendors, such as Nokia, Ericsson, and Huawei. Some operators already decided to shut down 2G services in 2017 as they see the demand for 4G services increasing every year. Most operators, however, expect a fairly lengthy period when Diameter and SS7 support are needed as the industry transitions to 4G.
In response, many vendors offer a Diameter Interworking Function (IWF) which enables Diameter to work in parallel with legacy SS7 protocols. Operator strategies for dealing with SS7 and Diameter depend on their 4G market development as some operators have a majority of their subscribers on 2G and 3G. Using an IWF will save costs of operating duplicate networks, while also delivering the services for 2G, 3G, and 4G subscribers.
This research uncovers strategies to deal with the evolution from 2G/3G SS7 protocols to 4G Diameter protocols with continue support via IWF.