Understanding Mobile Backhaul

In a network of core routers, edge routers, access networks, and other components, the network paths that exist between the core network and edge subnetworks are known as backhaul. This backhaul can be designed as a wired backhaul setup or a wireless backhaul setup or as a combination of both on the basis of your requirement. In a mobile network, the network path between the cell tower and service provider is considered to be backhaul and is called mobile backhaul.

Mobile Backhaul Application Overview

This topic provides an application example (see Figure 1) based on the mobile backhaul reference model where customer edge 1 (CE1) is a base station controller (BSC), provider edge 1 (PE1) is a cell site router, PE2 is an M Series (aggregation) router, and CE2 is a BSC and Radio Network Controller (RNC). The Internet Engineering Task Force (RFC 3895) describes pseudowire as “a mechanism that emulates the essential attributes of a telecommunications service (such as a T1 leased line or Frame Relay) over a PSN” (Packet Switching Network).

Figure 1: Mobile Backhaul Application

For MX Series routers with ATM MICs with SFP, the mobile backhaul reference model is modified (see Figure 2), where the provider edge 1 (PE1) router is an MX Series router with an ATM MIC with SFP. The PE2 router can be any router, such as an M Series (aggregation router) that might or might not support swapping (rewriting) of virtual path identifier (VPI) or virtual circuit identifier (VCI) values. An ATM pseudowire carries ATM cells over an MPLS network. The pseudowire encapsulation can be either cell relay or AAL5. Both modes enable sending of ATM cells between the ATM MIC and the Layer 2 network. You can configure the ATM MIC to swap the VPI value, VCI value, or both. You can also disable swapping of the values.

Figure 2: Mobile Backhaul Application on MX Series Routers with ATM MICs with SFP

IP/MPLS-based Mobile Backhaul

• Flexibility to support converged networks that accommodate both IP and legacy services (leveraging proven circuit emulation techniques).

• Scalability to support emerging data-intensive technologies.

• Cost-effectiveness to compensate for rising levels of backhaul traffic.

M7i, M10i, M40e, M120, and M320 routers with 12-port T1/E1 interfaces, 4-port Channelized OC3/STM1 interfaces, and MX Series routers with ATM MICs with SFP, with 2-port OC3/STM1 or 8-port OC12/STM4 circuit emulation interfaces, offer IP/MPLS-based mobile backhaul solutions that enable operators to combine diverse transport technologies onto a single transport architecture, to reduce operating costs while enhancing user features and increasing profits. This architecture accommodates the backhaul of legacy services, emerging IP-based services, location-based services, mobile gaming and mobile TV, and new emerging technologies such as LTE and WiMAX.