TPACK proposes a two-stage approach to Mobile Backhaul based on taking advantage of existing SONET/SDH and PDH infrastructure while preparing for transition to Connection Oriented Packet Transport based networks.

With the introduction of higher speed mobile data servides based on CDMA EV-DO and HSPA+, data traffic as a proportion of overall mobile traffic is expected to increase. Carriers with existing 2G and 3G networks require a migration strategy that not only prepares them for the future increase in packet data, but does not jeopardize existing profitable services based on voice and SMS.

TPACK proposes the following migration path maximizes re-use of existing SONET/SDH and PDH infrastructure and ensures a smooth transition to a fully packet-based network:

• Phase 1: Use SMARTPACK NG-SONET/SDH and SMARTPACK NG-PDH solutions to delivery support 2G, 3G and 3G+ networks while data service traffic is growing
• As part of phase 1, introduce Metro Ethernet Forum (MEF) User Network Interface(UNI) to support migration
• Phase 2: Use SMARTPACK PBT or SMARTPACK T-MPLS to replace the SONET/SDH network while maintaining the MEF UNI interface introduced in the previous phase.

In phase 1, a combined aggregation solution can be used to transport 2G, 3G and 3G+ traffic over both NG-SONET/SDH and NG-PDH. Both of these technologies use ITU-T defined Generic Framing Procedure (GFP), Virtual Concatenation (VCAT) and Link Capacity Adjustment Scheme (LCAS) to efficiently transport packet data over existing SONET/SDH and PDH infrastructure. See more here.

In the diagram above, the TPACK SMARTPACK NG-PDH Solution is shown, which combines NG-SONET/SDH and NG-PDH aggregation in a single line-card solution together with a Carrier Packet Engine for advanced layer 2 processing and traffic management. The TPX2530 Carrier Packet Engine provides an integrated packet processing and traffic management solution that supports multiple packet technologies, while the TPW48-P Ethernet over NG-PDH/SONET/SDH aggregation packet mapper offers complete flexibility in delivery of services.

This combined solution can support delivery of 3G and 3G+ Mobile Services by simply adding a linecard to an existing SONET/SDH Add Drop Multiplexer (ADM) or Mulit-Service Provisioning Platform (MSPP). Pseudowire technology is used to support existing ATM services transport over SONET/SDH networks utilizing the MEF UNI interface. A pseudowire is an emulation of a native service over a packet switched network. The native service can be legacy services such as TDM or other packet services such as ATM and Frame Relay.

In phase 2, the SONET/SDH network is replaced using Connection Oriented Packet Transport technologies, such as PBT/PBB-TE and T-MPLS.