As Mobile Video and other bandwidth-hungry mobile applications dominate the wireless communications infrastructure, wireless backhaul — the transfer of traffic from a wireless base station back to the core network (and ultimately the Internet) — become critical. In the past, T1s and E1s were used to do this, but increasing bandwidth demands encourage the deployment of fiber, which can be expensive. The latest approach is to use point-to-point wireless backhaul technologies, or a combination of wireless and fiber. In this six-part series, we take a look at what’s happening with wireless backhaul today.
The next player we shall examine is Juniper Networks which has some remarkably flexible approaches to mobile backhaul, where bandwidth-hungry service demands have put mobile operators under extreme pressure.
Nikhil Shah, Director of Mobile/Convergence Solutions at Juniper, says, “We’ve made some announcements recently and we are bringing some unique things to the market. First of all, in the past we positioned point products in the market, but now we’re building completely integrated end-to-end solutions and particularly pulling network management into the mix. We realize that, for mobile operators, a key challenge has been, for example, in the case of Cingular (News - Alert)/AT&T, there are 60,000 cell sites. So deploying this kind of equipment on cell sites in various types of locations is an involved process and we can make things simple from a network management perspective and make it so that it requires minimal user intervention. These are the key areas in which we have focused our efforts as we bring new solutions to market.”
“Having attended various backhaul conferences, my view is that fiber and point-to-point microwave are becoming more prevalent,” says Shah. “The U.S. and indeed the North American wireless market employs base stations where most of have TDM-based connections, in particular T1 lines. In Europe, however, 60 or 70 percent of the backhaul is done with microwave. In the APAC it’s a mix of fiber and microwave. Looking at the European model, they add point-to-point microwave as the bandwidth demand goes up, then when the links reach a sort of hub location, the microwave links can be run as high as an OC-3 bandwidth, and then it’s handed over to a wireline network from that point onward, such as fiber,” says Shah. “In many cases it doesn’t make sense to bring copper or fiber all the way to remote locations. It’s not economically feasible. Point-to-point microwave can be used as a wide area aggregation technology, and then the aggregated traffic can travel over fiber.”
“Going forward, you’ll see microwave technology getting more traction in the U.S. market as well, driven by some of the higher bandwidth WiMAX (News - Alert) deployments,” says Shah. “Microwave historically supported TDM links, but there’s been a great deal of interest in Ethernet, base stations are getting Ethernet interfaces, and so people are interested in supporting Ethernet over the microwave links. The Ericssons, Nokias and Alcatel-Lucents of the world are driving this. In 2008 we’ll see deployments with Ethernet interfaces right into the base stations.”
“Juniper’s role in all of this is helping that existing deployments of 2G and 3G radios coexist with 4G radios,” says Shah. “For the next five to seven years you’ll still see existing deployments of 2G base stations which typically support 2 to 4 T1s coming out of the base stations. In 3G and the AT&T/Cingular’s of the world, there are still T1 TDM lines coming out of the base stations, but they’re running ATM in multiplexing mode over those T1s. 4G audio and 3G UMTS radios will see Ethernet interfaces on the base stations. The need for all of this to coexist means that we must support all of these different transport technologies, and that’s exactly why Juniper has developed our Juniper Networks BX 7000 Multi-Access Gateway (News - Alert), which can handle TDM, 2G, 3G ATM and Ethernet coming out of the new base stations. All of these can connect to this device and work with various transport technologies such as a packet-based backbone. It allows operators to smoothly scale up their network, since T1 lines are not scalable enough to support the huge bandwidth demands that is starting to appear.”
Juniper’s BX 7000 can transport TDM, ATM and packet traffic over IP/MPLS using pseudo-wire emulation technology. Designed for the space and environmental constraints of the cell site, the BX 7000 supports common uplink types such as copper, Ethernet and DSL and emerging technologies such as WiMAX and LTE. Additionally, the product supports a range of timing synchronization options, while a slot for field-replaceable timing modules provides “future proofing”. By deploying the BX 7000, mobile operators can thus retain their existing investments in 2G and 3G cell sites while enjoying the benefits of IP/MPLS-based transport. Services can be migrated gradually, for example, by offloading the high-growth data transport as a first step.
The BX 7000 is part of Juniper’s best-of-breed mobile backhaul solution, which addresses an operator’s current OPEX (News - Alert) and bandwidth challenges while ensuring that there’s a path for future migration to 4G technologies. This solution includes Juniper’s M-series Multiservice Edge Routing portfolio, its MX-series Ethernet Services Routers and JUNOScope management framework software. When deployed together, these products create a complete wireless network architecture.
“Our solutions enable operators to use Ethernet transport, complemented by MPLS, and so instead of using TDM all the way from base stations to the base station controller, they can now use a packet-based backhaul network in the middle,” says Shah. “That drives down the cost point and greatly enhances scalability.”
Richard Grigonis is Executive Editor of TMC (News - Alert)’s IP Communications Group. To read more of Richard’s articles, please visit his columnist page.
Edited by Jessica Kostek