The mobile telecommunications industry is rapidly changing. The move to 3G and 4G is rapidly expanding the speeds of mobile phones, but the lines that connect cell towers to the Internet are being overwhelmed by the ever-expanding traffic.
With ninety-percent of cell sites without fiber connectivity, many mobile carriers are beginning to look at also using point-to-point wireless for backhaul. 1Velocity believes that mobile backhaul networks will soon be a mixture of landlines (copper and fiber) and point-to-point wireless (microwave and millimeter-wave).
Mobile Data Traffic is Exploding
In September 2009, AT&T revealed that data traffic had increased 5,000 percent over the last three years. They also announced that AT&T would skip 3.5G HSPA+ (7.2 Mbps) and go straight to 4G LTE (10 Mbps+) to keep up with demand.
AT&T is not alone. Verizon has the nation’s largest 3G network and will launch 4G LTE in 20-30 markets in 2010 with speeds up to 8-12 Mbps. And Sprint joint-ventured with Clear, which has already launched 4G WiMax in 14 markets with speeds up to 10 Mbps. (LTE and WiMax are two competing standards for achieving 4G speeds.)
“The popularity of new 3G devices such as the iPhone and BlackBerry 3G has increased the use of data, putting the backend networks under strain.”
How the iPhone is Driving a Wireless Bandwidth Boom, GigaOm
The Data Traffic Boom is Overwhelming Mobile Backhaul Networks
In the past, a cell phone call was transmitted from the cell phone to the cell tower wirelessly, and the signal then traveled over T1 landlines from the cell tower across town and out to the world.
A single T1 has 24 channels for phone calls, but that’s only 1.5 Mbps of bandwidth. A single 3G smartphone can transmit 3.6 Mbps of data all by itself.
That means a cell tower needs at least two T1s for every 3G user. And 4G smartphones are expected to transmit more than 10 Mbps. Much like a highway, when there is too much traffic on the backhaul network, everything slows down and users cannot get on.
Backhauling data traffic to the Internet has rapidly become the most expensive part of a mobile network, accounting for as much as 30 percent of operating costs. There are only so many T1s a carrier can connect to a cell tower. 4G provider Clear already requires 30-100 Mbps at each cell site. That would take twenty to seventy T1 lines!
“For mobile carriers, the largest network expense is backhaul…
The conversion to an-Ethernet-based IP-enabled network architecture is inevitable. This will occur not only to handle an increase in new applications and mobile users, but to drive down the rapidly rising cost of backhaul.”
Bandwidth above 10 Mbps typically requires fiber, but ninety-percent of U.S. cell sites are without fiber>. And after permits and trenching, bringing in fiber usually costs tens of thousands of dollars per site.
“For many copper-fed cell sites today, operators need to integrate a platform into their network that supports IP services without requiring them to forklift upgrade to expensive fiber infrastructure.
Service providers are searching for technologies that provide lower cost and more effective ways to meet the demand for bandwidth capacity while lowering both capex and opex.”
Backhauling Data with Point-to-point Wireless
In some ways, Clear/Sprint has been dealing for years with the issues with which AT&T and Verizon are now grappling. Although Clear is using WiMax instead of LTE and does not transport phone calls on its network (or deal with synchronization issues), they are still the first national carrier to deploy a mobile wireless network with 4G speeds.
Clear’s CTO recently stated that Clear requires 30-100 Mbps backhaul at each cell site. And Clear prefers Ethernet over legacy TDM. But the real news was that Clear backhauls 90 percent of its traffic using point-to-point wireless links.
Point-to-point wireless can be deployed more quickly and cost-effectively than ground fiber. And though microwave is typically limited to 155 Mbps, Clear has also begun using millimeter-wave licensed links for backhaul capacity up to 1 Gbps. In fact, Clear is the largest licensee of millimeter-wave spectrum in the United States.
Millimeter-wave Wireless Fiber
Also known as wireless fiber, millimeter-wave spectrum (71-95 GHz) can transport 1 Gbps Ethernet over distances of a few miles. Millimeter-wave can be used for the last-mile or as a middle-mile solution to backhaul lower-bandwidth microwave.
After Clear, the second largest licenseee of millimeter wave spectrum among U.S. carriers is 1Velocity, a metro Ethernet carrier based in Nevada. Since 2006, 1Velocity has licensed millimeter-wave links to build its own self-healing metro Ethernet rings in Las Vegas and Reno.
Encompassing over 100 locations in Las Vegas and Reno, 1Velocity’s metro Ethernet network provides carrier backhaul, Ethernet private lines, and Internet access from 8 Mbps to 1Gbps to other carriers, public safety, government, healthcare, gaming, transportation, financial, and professional services organizations.
Millimeter-wave and microwave are line-of-sight technologies, so 1Velocity can often provide service to locations other carriers cannot. And since 1Velocity is completely physically diverse from the LECs, carriers can get best-case redundancy with a combination of point-to-point wireless fiber and ground fiber.
Mobile bandwidth demand is growing at an incredible rate. Companies are investing today to catch-up and prepare for the future. The growth will continue as wireless 4G replaces home Internet and IP video matures. Cisco estimates mobile data will double ever year through 2013. NPRG forecasts double-digit CAGR through 2013 for the mobile backhaul market.
AT&T is investing billions to expand their fiber backhaul, as is Verizon. But while cell towers have traditionally been backhauled by T1 landlines, 3G and 4G networks will likely be backhauled by a combination of Ethernet over fiber and Ethernet over point-to-point wireless.
Clear today is seeing the traffic demands that the other carriers will begin to see starting in 2010. Clear has chosen Ethernet over wireless (microwave and millimeter-wave) point-to-point links for 90% of its backhaul. 1Velocity believes that mobile backhaul networks will soon be a mixture of landlines (copper and fiber) and point-to-point wireless (microwave and millimeter-wave).
Point-to-point wireless over microwave and millimeter-wave spectrum can reliably deliver up to 1 Gbps of bandwidth to locations without fiber. With point-to-point wireless, carriers can obtain a second path that is completely diverse from ground infrastructure to get bandwidth where they need it and improve reliability.