Architecting future-proof mobile backhaul networks

Page 4 of 4

 

Coexistence, interoperability, roaming, and handover between LTE and existing 2G/3G networks and services are inherent design goals, so that full mobility support can be given from day one. In LTE networks, IP is the only protocol used to support connectivity between the different mobile nodes as defined by 3GPP. To achieve, any-to-any topology for LTE backhaul, the Broadband Forum has recommended leveraging L2VPN (Layer 2 Virtual Private Networks) and L3VPN (Layer 3 VPN such as Virtual Private LAN Service [VPLS] and Border Gateway Protocol [BGP]/MPLS based VPNs).

Hybrid IP/MPLS and TDM backhaul architecture for 2G/3G

In a hybrid model, carriers can build out capacity to accommodate the data traffic growth without having to re-engineer the voice network (leave voice on existing TDM networks). Mobile operators can leverage cost-effective alternatives such as Metro-Ethernet networks or existing assets to support data traffic (for example, using the DSL infrastructure in Western Europe to offload the data traffic from the cell site). Deploying a hybrid model allows operators to develop greater familiarity with IP/MPLS technology and integrate voice traffic into the packet-based infrastructure at a later date. In a long run, All-IP backhaul network is going to be winner.

Timing Synchronization

Synchronization is critical to maintain good voice quality, reduce interference and manage call handovers between base stations. There are several approaches to achieve this timing synchronization, including Synchronous Ethernet, Adaptive Clock Recovery and IEEE 1588 v2. Network architects must consider which of these methods to use and ensure that their equipment vendors provide the necessary support while migrating to packet based backhaul.

To assist in this area, the Broadband Forum is assessing various requirements for supporting clock distribution to the base stations, including frequency, phase, and time synchronization. The Forum is looking at different clock distribution scenarios over mobile transport network, and provides recommendations in the context of QoS, resiliency, and efficient distribution based on topology (Point to point or point to multi-point).

Matching SONET/SDH type reliability with IP/MPLS

Synchronous optical networking and synchronous digital hierarchy (SONET/SDH) is known for its high reliability and fast recovery from failures, and therefore, carriers expect that new packet based backhaul will match that level of resiliency. IP/MPLS has already proved itself in core networks to be as reliable as SONET/SDH in many carrier deployments. The combination of Fast Re-Route (FRR) and carefully engineered primary and secondary Label Switched Paths (LSP) allows IP/MPLS-based network to recover in tens of milliseconds—on par with SONET-based networks.

Managing and troubleshooting IP/MPLS-based networks

In the past there was a misconception that IP/MPLS was difficult to manage and complex to troubleshoot, resulting in higher operating expenses. Carriers have been understandably reluctant to move to a new transport technology unless they were confident in its operation, administration and management (OAM) tools.

With years of successful service provider deployments around the world, IP/MPLS now includes a robust set of standards-based OAM tools that greatly reduce troubleshooting time, such as MPLS LSP-Ping, trace route, Virtual Circuit Connectivity Verification (VCCV) - test pseudo-wire state as well as Bidirectional Forwarding Detection (BFD) - a hello protocol to connectivity, amongst others.

 

By Robin Mersh and Nikhil Shah, Broadband Forum

Robin Mersh, Chief Executive Officer, Broadband Forum

Robin Mersh joined the Broadband Forum as Chief Operating Officer in July 2006, and was promoted to Chief Executive Officer in July 2010. Robin has authored many articles and has spoken at and chaired many broadband industry conferences and exhibitions. He has worked in the telecommunications industry for over 18 years, starting at Cable & Wireless and then moving on to BT before meeting his wife and moving to the US in 1999. Robin has worked in business development and alliance management for various OSS software companies in the United States, mainly in network and service provisioning and activation, where he negotiated and managed several large OEM agreements. He is originally from Cambridge in the United Kingdom. He received a Bachelor of Arts degree with honors from Queen Mary and Westfield College, University of London in 1992.

Nikhil B. Shah, Chairman, International Development, Broadband Forum

Mr. Shah is a Head of Wireless Segment Development, for Asia/Pacific region at Juniper Networks. He is responsible for developing wireless business, strategy, solutions, and partnership initiatives. He also served on the board of Broadband Forum from 2006 – 2010, where currently he is a Chair of International Development. Mr. Shah has over sixteen years of global telecom industry experience including living in US for 12 years before moving to Asia. He is a frequent speaker at various industry conferences.

• Start
• Prev
• 1
• 2
• 3
• 4
• Next
• End