Dark Fiber Makes a Comeback. Here’s Why.

Dark FiberWireless operators have quietly embarked on acquiring dark fiber – a trend that was picked up in 2013 and accelerated in 2014. Verizon is leading this activity and rolling out dark fiber to their cell site. But why specifically have carriers decided on dark fiber rather than continue lease capacity?

I think the answer has to be looked at from the perspective of long-term developments which matches the time-frame for leasing dark fiber which ranges between 10 to 20 years, and is typically closer to 20 years. Looking at that time-frame, we note that: Read more of this post

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Further Enhanced ICIC (FeICIC)

FeICIC LTE-AdvancedGuest post by Faris Alfarhan*

In an earlier post, R10-LTE enhanced inter-cell interference coordination (eICIC) techniques for heterogeneous networks were discussed, along with the concept of small cell range expansion. The purpose of cell range expansion is to offload more traffic from macro cells to small cells and hence achieve larger cell splitting gains. By adding a cell selection bias, the service area of small cells increases and more users are offloaded to small cells. The need for heterogeneous networks interference management schemes stems from the fact that users in the small cell range expansion area are vulnerable to stronger interference signals than useful signals from the associated serving small cell. In the previous post, it was explained how time domain partitioning based eICIC schemes – known as Almost Blank Subframes (ABS) – could be used to control the interference on the data channels in the range expansion region. Further, carrier aggregation based techniques – known as Cross Carrier Scheduling – could be used to control interference on the control channels (such as the PDCCH, PCFICH, and PHICH channels). However, R10 eICIC schemes did not address interference control on cell-specific reference signals (CRS), which cannot be blanked in order to ensure backward compatibility with R8 and R9 UEs. In this post, R11 improvements to eICIC schemes are discussed, along with the shortcomings of R10 eICIC schemes. First, the concept of Reduced Power Almost Blank Subframes (RP-ABS) is explained along with its advantages over ABS. I then discuss the R11 techniques of Further enhanced ICIC (FeICIC) to control the interference on CRS resources. Read more of this post

The Long-Term View on Small Cells

Long-Term View Small CellsThe evolution of wireless networks to a HetNet architecture is inevitable, but the question for industry players and investors is what form will it take. This is because there is no single approach to small cells, but rather there are multiple ways to densify the network. Making misplaced bets is common in the technology space, mainly because of the myriad of cause and effects that take place where technology is only a factor among many other factors, and at times a minor one in comparison. Read more of this post

The Coming of Cloud RAN

Cloud RANThe evolution of wireless communications has spawned many innovations but the cellular concept where base stations are dispersed to meet coverage and capacity requirements remains constant. This is about to change, sort of, if Cloud Radio Access Network (CRAN) architecture lives up to its vision. What makes CRAN such an interesting development is that it leverages advances in a number of different fields to pull together a solution to two perpetual problems facing network operators: cost reduction and increased capacity. Read more of this post