Harpinder S. Matharu, Xilinx
EETimes (10/22/2012 5:11 PM EDT)
Small cells are low-powered radio access nodes that may operate in both the licensed and unlicensed spectrum and that have a range of 10 meters to 200 meters, as compared to macrocells, which might have a range of a few kilometres. Small cells have long existed in the network with the purpose of filling in coverage gaps. The recent resurgence in interest in these small cells is being driven primarily by market demand for higher network capacity to host existing and new data services. Cell coverage continues to be an issue due to limited indoor penetration at higher transmission frequencies. For such cases, small cells are likely to play a vital role in providing indoor coverage and capacity. While small cells hold the promise of a faster deployment, deeper reach, and a much lower cost, there are significant challenges associated with their deployment. In order to overcome these deployment challenges, small cells must coexist with macro cells and other small cells located in the same vicinity, satisfy backhaul connectivity issues, and provide programmability to ease deployment and management to contain the operational complexity that they add to the wireless networks.
In parallel, macro cells have been evolving from a monolithic architecture to a distributed architecture, with a significant increase in investments to remote radio heads and active antenna technologies. This opens the door to using alternative architectures to increase network capacity and coverage. Therefore, the question of small cell adoption – how fast and how many – depends on how quickly the wireless industry overcomes the deployment hurdles for small cells as well as on the level of adoption of distributed macrocell architectures. This article discusses base station trends and their evolution, the rationale for using small cells, and the backhaul challenges that the growth of wireless networks will face in the coming years.
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