Soon cell towers will start following you

Intucell is working with an unnamed North American operator to build a new kind of self-aware cellular network. The Israeli-startup’s self optimizing network (SON) technology will turn what has hitherto been a static cellular grid into a dynamic system of constantly expanding and shrinking cells that can follow customers as they move throughout the network. In the near term, that means more customers getting faster speeds more often and dropping fewer calls. But long-term SON techniques like Intucell’s will become foundational technology for the future heterogeneous network.

First, some background about how wireless networks behave: A cellular network is a shared resource, meaning a cell’s capacity is divided among all of the customers currently within it, but the overall capacity of that cell is determined by where all those customers happen to be within the cell. If customers are all at the cell’s perimeter where the air link is most fragile, then the overall capacity is small. If those customers are clustered in the center, then the overall capacity available increases.

Furthermore, a cell’s capacity is always a weakest link type of situation. An outlying device at the edge of the cell will degrade the capacity available to customers at its center. Intucell’s technology is designed to solve that problem by identifying those situations in which a cell’s capacity isn’t being utilized to its fullest. The SON intelligence forces towers to talk to one another and recognize when outliers at the cell’s fringes are spoiling the party for rest. Intucell then tells neighboring cells to expand to grab those edge customers, while the original cell shrinks, boosting the capacity available to remaining customers within it.

“Until now optimizing a radio access network has been sort of a type of witchcraft,” Intucell CEO Rani Wellingstein in a recent interview. “Engineers would typically retune networks on a weekly or a monthly basis. That kind of model was good for when traffic was not so dynamic, but today congestion is moving dynamically through the network.”

But wait, SON can do more

Last month, Israel’s Pelephone became the first operator to commercially deploy Intucell’s technology network-wide, though Wellingstein said other Tier I operators globally are now using the SON system. In North America, a major carrier is using the technology in a commercial trial in two cities, Wellingstein said, though he wouldn’t reveal which one.

Operators are using the technology to retune the network every few minutes, which it allows to jigger the network for the changing traffic patterns throughout the day. But Wellingstein said the SON platform can retune in real time, which would allow the network to account not just for where its customers are but where they will be.

Take the example of city bus with a 4G connection distributed to all of its passengers through Wi-Fi. Normally passengers would experience huge fluctuations in bandwidth as they moved from a cell’s center to its edge and crossed over into neighboring cell’s edge and so forth. But by anticipating where that hotspot-on-wheels is going, the network could grow the cell it’s driving through, keeping its edge well ahead of the bus and thus maintaining its high-bandwidth connection. Meanwhile, SON intelligence would also tell a neighboring cell running on a different frequency to expand, so that both cells overlap. When it’s finally time for the first cell to relinquish its connection to the second, the bus would already be well within that second cell’s perimeter and instantly have access to a much higher-bandwidth connection.

Intucell estimates these techniques can reduce dropped call rates by 10 percent and even more significantly, boost overall data capacity throughout the network anywhere from 30 percent to 50 percent. That will have a huge impact on how carriers plan for future growth. Not only will they be able to offer faster and more consistent speeds, it would allow them to slow down the endless cycle of capacity upgrades as more customers sign up for 3G and 4G services.

Enter het net

Ultimately, SON will have its biggest impact as the industry moves to the next phase of cellular design: the heterogeneous network, or het net for short. Rather than build networks merely as a bunch of macro cells in a grid, operators will throw a myriad of small cells into the mix, all of which live inside of their macro brethren. The big network will be used to provide an umbrella layer of coverage, while the ‘small’ network of millions of metro-, pico-, and femtocells will supply enormous quantities of capacity.

We’re already starting to see the beginnings of het net with public Wi-Fi networks. Either at the behest of their carriers or on their own recognizance, customers are offloading enormous amounts of data onto free or cheap Wi-Fi access points. But operators like Verizon Wireless hope to recreate such topologies using their own spectrum. The complexities of such a network are enormous. Not only would they involve individual carriers managing networks of hundreds of thousands – if not millions — of nodes rather than thousands, but those small cells would need to utilize the same spectrum as the over-arching macrocells above them. That means highly dynamic network organization technologies like SON will be necessary to wrap those cells around one another. Otherwise, het net would just be another word for noise.