Typically, a small number of DS1s has been sufficient to service 2G and 2.5G base stations, but with the data capacity needed for advanced 3G and 4G HSPA/LTE applications, new strategies and even new technologies being evaluated.
More network capacity translates to more backhaul capacity. This additional capacity can be more efficiently delivered in IP/Ethernet. Among the many technologies available, IP/Ethernet is consistently recognized as the transport media of choice for expanded backhaul services.
For many operators the introduction of Ethernet will be an overlay on top of existing TDM (voice) network connections given their huge investment in their TDM infrastructure. This will typically involve gradual migration using data overlay, with a decision at some future point to further migrate to an all-packet-based network. The transition phases may well include instances where there is a need to transport Ethernet alongside TDM, or Ethernet over TDM, and do so in a flexible, secure and cost efficient way.
It is clear is that the traffic requirements in carrier networks are becoming more advanced. To support real-time, two-way digital communications, an IP-enabled, communication pipeline must be established.
Our paper reviews the technology choices that are available to support legacy TDM and IP-based services when migrating to IP/MPLS. Network migration should consider the many demands such as seamless migration, increased capacity, cost, and security. Hybrid networks that can transport native TDM alongside native IP are the best solution to successfully tackle the many requirements for mobile carrier networks.