Densifying the networks with small cells is a key part to making 5G a reality, but the most dense small cell networks are still in 4G.
Network densification has been used in 4G LTE for a while. As the 3GPP standards committee meets in Busan, South Korea this week, let’s take a look at some recent network densification efforts in 5G.
Networks need to be made more dense or just extended in areas with high concentrations of mobile users, such as urban areas and large public venues. As with all 5G, the tech industry anticipates explosive growth of applications, some of which will require massive bandwidth. 5G network densification has become a priority in both fixed and mobile wireless for network operators.
One method of network densification is to use the heterogenous networks or hetnets, which consist, among other iterations, of an army of small cells precisely placed to extend existing networks so they can provide enough coverage for more devices and for the use of millimeter wave spectrum, which needs additional cells close to each other due to its short propagation range. A good explanation can be found on this 3GPP blog.
C-RAN (cloud or centralized radio access networks) is another route that supposedly avoids any interference that having so many small cells so close by virtualizing the radios into one cell, not multiple cells. CommScope provides a good basic explanation of C-RAN in small cells. Centralized RAN also enables operators to save money in several ways.
Small Cell Forum, a carrier-led organization also having an event this week in London, says two work streams are helping hetnets become viable. The forum points to use cases for hetnets and 5G championed by two operators:
- Deploying hyperdense networks (championed by AT&T, Jio)
- Enabling digitized enterprise (championed by Orange, Vodafone)
Not a 5G trial, but worth mentioning, is Sprint’s deployment of 200,000 “Magic Boxes” to consumers and businesses in more than 200 cities. Sprint says it is one of the largest small cell deployments in the U.S. Magic Boxes are manufactured by Airspan, which will probably pick up Qualcomm’s 5G NR chip next year when it launches.
Here’s a short list of various densification efforts in no particular order:
- AT&T’s Project AirGig Trials: The famous “puck” brings ultra-fast Internet over power lines. Installed in the U.S. state of Georgia on Georgia Power’s power lines. This trial is actually more about 5G broadband but could be used for densification. “Your small cell layer, your densification layer that you built today is being built in such a way that you can add millimeter wave spectrum,” said Gordon Mansfield, VP RAN and device design for AT&T at SCWS in 2017.
AT&T’s Project AirGig Trial puts a small cell on existing infrastructure. “It could one day deliver internet speeds well over 1 gigabit per second via a millimeter wave (mmWave) signal guided by power lines,” says AT&T in a statement.
- China Mobile‘s base station trials. Again, not small cell network densification but as the GSMA said, “Early commercial rollouts are likely to require investment in small cells and transmission upgrades, with fiber backhaul (up to 10 Gbps) to support sub-10 ms latency.”
- Samsung’s multi-device trial at a stadium in Japan.
- The Winter Olympics in South Korea: Indoor coverage was difficult because with millimeter wave, penetration was an issue.
Again, examples are plentiful for 4G deployments of small cells. Another example, infrastructure company Crown Castle deployed a network along the route Pope Francis took in a 2015 visit.
Crown Castle’s small cell deployment in Philadelphia, Pa., is 4G, not 5G.
Editor’s note: This story has been updated.
