Editor’s Note: This article originally appeared in RCR Wireless News’ January Special Edition Wireless Infrastructure: The Engine for Economic Recovery. Look for our March Special Edition, coming soon.
Wireless carriers are moving at ever-increasing speeds to roll out ever-increasingly speedy data services in an attempt to stay ahead of booming consumer demand, but many industry watchers expect the ability to transport that data from the base stations back to the wired network could throw a wrench into rollout plans.
A recent report from investment research firm Canaccord Adams predicts that by 2015, Verizon Wireless and AT&T Mobility will require anywhere from 250 to 720 megahertz of wireless spectrum each to handle consumer mobile data demands, and all of that traffic needs to find some way from the tower to the Internet backbone.
According to ABI research, about 1.3 exabytes (1018) of data were transferred from mobile devices in 2008. Cisco Systems estimates that by 2013, 1.6 exabytes of data will be transferred per month. Yikes!
“Mobile networks are just going to become more needy as far as backhaul capacity goes since LTE (W-CDMA Long Term Evolution) and 802.16m (an evolved version of WiMAX expected to be deployed in 2012) will push edge of cell base station capacity requirements from 100 [megabits per second] to 300 Mbps in the 2011-2013 time frame,” noted Visant Strategies in a recent report.
The options
Today there are three standard methods to handle the backhaul of wireless communications: copper, fiber and microwave. Copper has been the standard method since wireless networks first began rolling out in the mid 1980s and is seen as a low-cost and relatively efficient way to handle voice traffic and a modest amount of basic data services. According to New Paradigm Resources Group, at least 85% of all U.S. cell sites are served solely by a local exchange carrier’s copper backhaul.
However, with the move to higher-speed wireless data capabilities as well as the highly penetrated wireless markets around the world, copper’s limitations are being exposed as insufficient and carriers are moving aggressively toward Ethernet-based solutions like fiber and microwave.
“The present increase in needed backhaul capacity is due mainly to the current deployment of HSDPA, EV-DO and mobile WiMAX, which are stretching traditional limits of copper-based backhaul throughout the wireless network, even in the middle network, and leading to an increased use of [point-to-point] microwave and bonded copper,” said Larry Swasey of Visant Strategies. “This will continue when HSPA+ and LTE are rolled out.
“Copper will remain relevant even in mature wireless markets due to bonded copper technology and higher speed DSL will be made possible by deeper fiber and hence shorter copper distances. Fiber backhaul will make some inroads in middle of network backhaul and lesser gains in edge of network backhaul,” Swasey added.
Fiber is seen as the most attractive option due to its scalability, though some question the ability to run fiber to every cell tower at a reasonable cost. Microwave takes out some of the cost concerns and deployment issues impacting fiber, but has to deal with other variables like interference issues with wireless transmission and corresponding quality of issue concerns.
In the U.S., Verizon Wireless and AT&T Mobility have made a point of highlighting their plans to run fiber to as many of their cell sites as possible to support their 3G and 4G networks. Clearwire Corp., which does not have the installed wireline base Verizon Wireless and AT&T Mobility have through their parent companies, has turned to microwave transmissions to backhaul traffic from its WiMAX network, a method that is popular internationally where wireline networks are not as robust as in the States.
Both options provide the backhaul support needed for higher-speed wireless data networks, and are expected to become the standard form of backhaul support for new cell sites. In-Stat predicts that over half of backhaul links by 2011 will be Ethernet.
“Overall base station sites in established mobile wireless markets will need lots of backhaul capacity,” noted Visant Stategies. “For example, in the United States, Visant Strategies sees less than 5% of sites in the middle of the decade utilizing less than 10 Mbps while at the same point in time 65% of all base station sites in the United States will be utilizing (or should be) 45 Mbps to 155 Mbps and over 155 Mbps in backhaul capacity.”
Fiber and microwave are also favored by operators as both solutions provide the scalability needed to meet current needs as well as future expectations. In-Stat provided similar analysis, noting it expected Verizon Wireless to not need 100 Mbps backhaul capabilities for its LTE network through its initial rollout in 2010.
Tower companies could be challenged by this rush for higher-speed backhaul capabilities as some older base stations may not have the necessary Ethernet equipment to support needed upgrades.
Backhaul costs a backbreaker
One challenge for carriers is the cost involved in implementing such backhaul solutions. Infonetics Research claims that backhaul operations account for up to 30% of a wireless carrier’s total operations costs.
For carriers like AT&T Mobility and Verizon Wireless that are part of multibillion-dollar telecommunication giants, these costs are seen as just part of doing business. But even these carriers have been watching their operational costs over the past several quarters due to the current economic stagnation.
But for others that have a closer look at the bottom line, these costs could prove a high hurdle to clear. Insight Research claimed that 90% of U.S. wireless backhaul is served by leased private lines, which Aurora Network Inc. said shows carriers “prefer to lease capacity even though microwave options are available that would allow them to own their own backhaul infrastructure.”
Clearwire, which was dinged by many industry observers for initial problems with backhaul equipment as it started rolling out its WiMAX network, has aggressively bolstered its microwave backhaul and has announced several deals with network providers to support that initiative. In-Stat noted that Clearwire’s current solution provides backhaul capabilities of between 30 and 40 Mbps.
“’Because of the costs associated with fiber, we see over the next 36 to 48 months a blended copper/fiber solution,” said Tom Huegerich, VP of global fiber for ADC Telecommunications Inc. “Not everybody is going to be able to afford fiber and money’s tight. I think carriers are going to pick the most strategic areas that will get fiber and other non-strategic areas that will have to do with copper. And even if there were no cost concerns, I’m not sure they can even get enough people to drop fiber to all cell sites.”
Cable opportunities
Cable companies that have an established network of high-capacity infrastructure already in the ground are another option for backhaul transport. While cable companies have so far shown little interest in getting in on the backhaul game, some think it’s only a matter of time before they take the plunge.
Aurora Networks claims cable companies have an advantage in that cable fiber nodes are in close proximity to up to 80% of the businesses in their markets, “most of which are situated in the commercially zoned locations where base stations are most likely to be found.”
Clearwire’s CEO Bill Morrow noted at the recent 4G World event in Chicago that while the company has reseller agreements and some financial investments from a number of cable companies, they have not yet looked seriously at using those embedded cable networks
for backhaul support for its WiMAX network.
Oth
ers note that while cable providers have extensive reach with their facilities, there may not be the necessary capacity to handle extra traffic.
“When you look at what they put out there, they did not put in a lot of extra fiber,” said ADC’s Huegerich. “You find in the MSO space that they have run a lot of low fiber, so they don’t have a ton of excess fiber or dark fiber in the ground. They are there though and I wouldn’t be surprised to see a big carrier lease capabilities from an MSO on a dark fiber. I don’t think it will be an issue with costs, I think it will be an issue of how quick you can respond.”
Regardless of which solution wireless carriers choose for their backhaul capabilities, those plans need to be robust if they want to feed the increasingly hungry data consumer.
