Lately we’ve written a lot about the heterogeneous network, or HetNet, exploring how today’s big-tower mobile grids will evolve into dense, multi-layered and tremendously high capacity networks. Given the complexity of such systems, it’s easy to imagine HetNet as a technology of the distant future, but the CEO of world’s largest mobile infrastructure maker Ericsson doesn’t think so. In fact, in an interview with GigaOM on Wednesday, Hans Vestberg said the fundamental building blocks of HetNet are already here.
HetNets have three major components. The first is an umbrella — or macro — network designed to provide ubiquitous mobile broadband coverage. The second is a dense network of small cells that supply enormous quantities of bandwidth in the high-traffic areas its most needed. The final component is a network intelligence that ties those networks together. According to Vestberg, the wireless industry has largely built the first and is actively deploying the second. The network intelligence is still in the works, but it won’t be long before it’s a commercial reality, Vestberg added.
There are already 1.1 billion mobile broadband subscribers globally, traversing networks comprised of millions of macro cells, Vestberg said. Only a small subset of them are LTE subscribers today, but LTE networks already cover more than 325 million people in North America and Asia.
“We’re at a tipping point,” Vestberg said. “You build the macro networks first, but we’re soon going to have very dense networks of small cells.”
The next step is Wi-Fi, which is already being deployed as a small cell technology globally. Major operators like Japan’s KDDI, Europe’s Orange and AT&T are starting deploy dedicated high-capacity access points to offload cellular network traffic. Hotspots aren’t quite HetNet, but it’s the first step toward building a layer of small dense cells that can supply enormous capacity at low cost, Vestberg said. Ericsson has already gotten a jump on the competition by buying up metro-Wi-Fi vendor BelAir Networks, which supplies hotspot gear for AT&T and many U.S. cable operators.
Wi-Fi will soon be augmented by metrocells and microcells moving that high-bandwidth under-layer off of the unlicensed airwaves onto carriers’ own spectrum, Vestberg said. With those small cells they will be able to pack the total capacity of a macro cell into a tiny radius, and as those small cells multiply they will make once scarce mobile bandwidth plentiful.
The final component — the network intelligence to control it all — will deliver the true promise of HetNet, allowing operators to manage Wi-Fi access points as if they were any other cell and tightly integrate metro-and microcells into their network hierarchies without fear they will interfere with each other or the over-arching macro grid. That technology is already out of Ericsson’s labs and will be available in its forthcoming small cell portfolio, Vestberg said.
“I think North America will be one of the first ones to get there,” Vestberg said. “They’ve already started with Wi-Fi. They will do HetNet on top of that.”
Vestberg cautioned that HetNet is a gradual evolution of cellular topology, not a distinct network unto itself – a carrier won’t suddenly one day turn on a network of 1 million cells. The name “heterogeneous” provides a good clue on these networks will come together – Wi-Fi, home and public femtocells, pico-and micro-cells will be deployed in different stages but will eventually come together to form a larger network whole.