Small cells key to LTE
Small cells are going to play a significant role in LTE network rollouts. Inevitably, just about every equipment vendor has a different take on how that will – or should – play out. I talked to three of them at LTE Asia in Singapore. Here’s what they said:
Wi-Fi integration is “mandatory”
Bob Cai, vice president of wireless marketing development at Huawei Technologies, says the chief features small cells must have to succeed are coordination with the macro layer and SON for easy installation. Also, they should support Wi-Fi.
“Integrating Wi-Fi will be mandatory for small cells, because most mobile data traffic can be offloaded to Wi-Fi. And it can be integrated into the mobile network,” Cai says. “We can integrate the access part and the gateway part into one box, and then you can switch between Wi-Fi and the mobile network.”
Cai also said Huawei’s small-cell solutions will also be able to utilize TDD spectrum as a backhaul option. “In markets where operators have TDD spectrum that they’re not using, they could use it to provide backhaul for pico cells.”
Skip the macro cells
Prof. Shahram Niri, director of LTE at NEC, says operators don't really need macro cells at all to deploy LTE, because small-cell solutions can serve their coverage and capacity needs at a cheaper TCO.
“Small cells should be the starting point for LTE deployments, because when you calculate the cost in terms of the cost per bit per square kilometer, using small cells instead of a macro cell can deliver [TCO] savings between 30% and 60%,” he says.
Niri acknowledges that early LTE adopters are starting with macro deployments. “We realize the prime objective for operators is to put up some coverage, create some noise and get something up and running. That will do the job. But when they’re forced to increase capacity to accommodate exponential traffic increases, macro can’t do it.”
Niri predicts that in two to three years, new LTE players will opt to roll out small cells first rather than deploy macro cells and add micro and pico cells after the fact. “You will have to install small cells anyway to increase capacity, and also because they make new services perform better in terms of faster speeds, better user experience, and lower power, which means less of a drain on the battery. And you will have to add them quickly because data traffic is growing exponentially.”
Big and small, deploy them all
Ip Hong, vice president and head of marketing group for telecoms systems business at Samsung Electronics, said that LTE operators should deploy macro cells and small cells at the same time when possible to mitigate potential interference issues early.
“Operators may need hot zones within a macro cell, which may consist of clusters of pico cells. That creates potential interference issues, which need to be mitigated,” he says. “Deploying both at the same time allows operators to manage that more effectively.”
Not surprisingly, Samsung’s approach is informed by its SmartCluster product (part of its “Smart LTE solution” line), which puts a premium on network optimization and interference management to enable operators to deploy fewer base stations.