GPON in Mobile Backhaul Final - TEC

1 1 gpon in Mobile Backhaul Ram Krishna, DDG (FLA), Mrs. Laxmi Director (FLA), Naveen Kumar ADG(FLA-II), , ADG(FLA-I) and Divya Sharma ADET (FLA) Telecommunication Engineering Centre, Department of Telecommunications, Govt. of India, New Delhi Abstract In a hierarchical telecommunications network the Backhaul portion of the network comprises the intermediate links between the core network, or backbone network and the small sub networks at the "edge" of the entire hierarchical network. Backhaul is the obligation to carry packets to and from that global network.

2 Backhaul generally refers side of the network that communicates with the global Internet or an Ethernet Exchange or other core network access location. This document describes how gpon Technology addresses the need for increased bandwidth, scalability and reliability in Mobile Backhaul networks while providing lower capital and operation expenses, backward compatibility and an easy migration path to an all IP network. 1. Introduction As Mobile Service Providers deploy 3G networks, subscribers are now using their smart phones for true broadband data services, such as Internet access and streaming video.

3 High-bandwidth consumption is no longer limited to the home -- and driven by the deployment of 3G and future 4G systems, fast growth is predicted for Mobile broadband adoption. In their market forecasts, industry analysts anticipate that data volumes will grow at an accelerating rate based on the broader range of broadband data services. At the same time, revenue per megabyte continues to fall, driven down by increasing competition and the introduction of flat rate pricing. To remain competitive, Mobile operators must be prepared to provide a network that can not only meet bandwidth demand, but also deliver a healthy profit margin.

4 To achieve this goal, new technology is required to translate this significant rise in traffic into revenue opportunities. 2 In the Mobile network, cell site base stations are connected to their network controllers by the Mobile Backhaul (MBH) network. Traditionally, this is a TDM network optimized for voice but this type of network does not cost-effectively scale to support the growth of Mobile data traffic. Consequently, it is critical that operators adopt an affordable Backhaul solution that does scale and provide end-to-end packet-based transport.

5 Looking specifically at the access portion of the Mobile Backhaul Network, about half of all cell sites today are backhauled by microwave, with the other half by wireline systems. In the case of wireline access, E1/T1 leased lines are typically used but these are expensive and their costs scale linearly with bandwidth, making them particularly unsuited to meet the bandwidth demands of Mobile broadband. One strategy for a packet-based wireline access network is to leverage gpon residential broadband deployments for Mobile Backhaul .

6 Figure 1 Cost challenges of 3G and 4G multimedia services mandate Backhaul optimization Source: 2012, Infonetics Research 2. gpon Mobile Backhaul System Architecture gpon , standardized in the ITU-T 84 series of recommendations, is one of the dominant point-to-multipoint (P2MP) fiber technologies being deployed today. For fixed line access, PON technology already provides proven cost and performance advantages over competing access technologies. The massive worldwide deployment of gpon networks, providing service to millions of users, makes the economics of gpon particularly attractive to Mobile carriers.

7 3 Figure 2 gpon Mobile Backhaul System Architecture Figure 2 show a typical gpon -based Backhaul deployment which supports both legacy TDM and IP networks. The L2 bridge aggregates all traffic flows with no need for routing in the RAN. Converged Packet Transport: A Platform Supporting Both E1/T1 and Packet The gpon element at the cell site that interfaces to the base station is the cell site gateway. Basic cell site gateway functionality includes termination of the gpon link on the network side and presenting physical interfaces to the base station.

8 At this time, the majority of cell site interfaces are E1/T1, with the availability of native Ethernet interfaces continuing to grow over time. Therefore, to realize the CapEx and OpEx savings that can come from the deployment and operation of a single converged MBH network, the cell site gateway must present to the base station: E1/T1 interfaces with a circuit emulation services (CES) interworking function for packet transport. Native Ethernet interfaces. With the next generation of radio networks such as high-speed packet access (HSPA) and long-term evolution (LTE) the capacity to/from the base station will increase significantly compared with today s requirement of a couple of E1/T1s.

9 In some cases the Backhaul capacity for a three sector site will be in the order of 100-400 Mbps. This clearly requires more backhauling capacity. Since cell-size is decreasing and fiber is driven deeper into the 4 network an attractive option is then to use gpon as a backhauling technology to/from base stations. Redundancy and Protection The Mobile Service Provider's service availability targets may lead, in some cases, to the addition of redundancy at key points in the network. In a gpon network the failure cause is fiber which can occur on the network side as well as towards ODN.

10 Network side standards protections techniques are implemented which provides protection on packet network for example RPR, Spanning protocol etc. On the other side two main types protection techniques are defined these are Type B and Type C . "Type B" redundancy scheme provides a second diversely-routed feeder fiber connects the optical splitter to a second gpon port at the OLT . On the other hand "Type B" redundancy scheme provides a second diversely-routed feeder fiber connects the PON port at ONT toward second gpon port at the OLT.