When you hear about the latest wireless technology, wires are probably the last thing to come to mind. However, mobile networks have always relied on a wired backhaul to connect cell sites to a mobile switching center – starting with copper-based T1s and E1s in 2G and 3G networks. And the role of the wired backhaul is even more critical to achieving the promise of next generation 5G services.
All of our mobile devices, data and video demands, smart home sensors, IoT devices and more are exceeding the capabilities of today’s 4G network. 5G is the future – promising 1,000 times more bandwidth, peak data rates of 10 Gbps, less than one millisecond latency, and 99.9999% reliability. These performance advancements will set the stage for a whole new wave of technological advancements, including virtual reality and autonomous vehicles, that will change the way we live and work.
5G and Small Cells
5G’s network architecture will look dramatically different than 3G or 4G networks. To achieve its goals of exponentially higher bandwidth with virtually no latency, 5G will use higher frequency millimeter waves (24 GHz and above). A shorter wavelength means that 5G can carry data faster than 4G, but at a much shorter range. While 4G wavelengths have a range of approximately 10 miles, 5G’s range is just a fraction – about 250 to 1,000 feet.
This limited range means that there needs to be a lot of 5G cell towers and antennas close to users everywhere. Instead of one macro cell site covering several miles, a small cell site may cover only hundreds of feet. And instead of hundreds of users sharing spectrum in a macro cell, a fewer number of users can share the same block of spectrum in a small cell – essentially giving each user higher data throughput.
5G and Fiber
5G providers will need to switch from the traditional macro cell model to low-cost small cell sites. For example, small cells can be installed on streetlamps and buildings throughout a neighborhood. As reported in a PwC paper “Why 5G can’t succeed without a small cell revolution,” an FCC commissioner estimated that the U.S. needs 800,000 small cells for 5G and International Data Corporation (IDC) expects over 2 million small cells by 2021.
This dense mesh of 5G cells need a backhaul connection. In 2015, 90% of cellular backhaul was through copper cable, 6% through fixed wireless microwave and 4% through fiber. However, fiber is the preferred medium for 5G, as a large number of light frequencies can be passed through a glass strand with very little loss and the signals aren’t affected by electro-magnetic interference (EMI) or radio frequency interference (RFI).
Hybrid Fiber-Coaxial Networks
HFC is also being considered as a potential backhaul alternative for connecting 5G small cells as it already reaches 93% of U.S. households, can support gigabits of downstream and up to 500 Mbps upstream capacity, and is already powered. That amounts to significant cost and time savings for dense small cell deployments. And the emergence of DOCSIS Timing Protocol (DTP) provides the precise frequency and time needed to support cellular applications.
Whether a carrier uses fiber, HFC or a mix of the two, the success of 5G wireless networks will be inextricably linked to the quality of the backhaul. The potential of 5G depends heavily on real-time data, driving the need for lower latency and more bandwidth.
Strategic Convergence of Fiber and Wireless
As a result, carriers are focusing their efforts on fiber optic cabling (and/or HFC plant) in their network, and we expect to see a convergence between traditional wireline/cable operators, who have the fiber optic plant, and cellular wireless carriers.
The story is less about which is better, 5G or fiber Internet. Rather, 5G and fiber complement each other.
While fiber offers the speed and performance to support our connectivity needs, a smartphone, self-driving car, or other smart sensor can’t connect directly to the fiber backbone. They need mobility. And that’s where we see fiber networks and wireless converge: fiber, or HFC, will be distributed everywhere close to end users, with 5G wireless stretching out to mobile devices in the last hundred or so feet.
5G enables the mobility and fiber enables the performance to create a next generation Internet experience capable of supporting our huge data and device demands.
Want to learn more about cellular service with mobile backhaul over DOCSIS? Contact our friendly Hitron team to find out more.