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June 29, 2015

Rethinking Small Cells

After reflecting on the week that I just spent at the Small Cell Forum, it’s clear that the view on outdoor small cells really hasn’t changed much.  Everyone now has a bit of pilot and trial experience under their belt, and we’re all still saying mass deployment is 12 months away, just as we have been saying for the past 3 years. However, during this time period no real outdoor volume deployments have occurred, and those few plans that had been announced have largely stalled and been delayed.

We keep trying the same thing and expect this year things will be different, yet it looks like the problem is being addressed in the wrong way. The industry has been taking our 30 years of experience from traditional mobile networks and fine-tuning it here and there to work in an urban street level environment. Antennas are getting a bit smaller on the backhaul side, and basestation and backhaul equipment are also getting smaller to enable street level installations. However, the processes being discussed to support rollouts have not changed much from traditional cellular deployments. The network rollout process is still comprised of site acquisition, network engineering, and then deployment by the field engineering team, followed by commissioning. These methods work exceptionally well when deploying small cells and associated wireless backhaul, and they have been very successful for trials and market pilots. Once they are completed, the basestations work as expected and the backhaul delivers the desired capacity, generally at the expected high availability SLAs.

The problem is that these processes do not scale to meet the small cell objectives, where we need to deploy 5-10 times as many sites in the same timeframe as a traditional deployment, and it needs to be accomplished at a fifth to tenth of the cost per site of a traditional mobile network. In order to meet these objectives, the entire industry needs to rethink small deployments. Operators will need to reinvent their processes, and equipment manufacturers will need to build the right features to enable the new processes. 

Engineering and site acquisition may need to change from per site activities done six months in advance, to city-wide activities done at the time of deployment. Operators may seek agreements to obtain site rights to a large number of sites, for example billboards on bus stops, but only select the actual location during deployment. This would also mean there will need to be dynamic engineering, with updates to the coverage plan, and backhaul network design occurring as sites and wireless backhaul links are being deployed. In the actual deployment phase, installation of the small cell and wireless backhaul will need to be completed within hours, instead of days. This not only requires a change in procedures, and installation standards, but it will also require equipment to do self optimization in order to minimize the amount of hands-on time required. 

At the same time, reinventing the cost per site will be critical to the small cell business case. Reduced engineering and installation time will result in costs coming down. However, equipment costs will also need to be reduced with optimizations for the small cell environment, such as reduced power and increased functionality. Integration of multiple functions into a single device will also become important to reduce costs. Cost and amount of labor will also be very important, so reusing crews that are already certified for the installation environment should be prioritized. For example, if the installation is occurring on a light pole, it will be important that the city crew certified to work on the light pole can quickly install the basestation and backhaul equipment without significant training. Operators will also need to make sacrifices in order to hit the cost targets. Network availability and protection may have to be reduced; IP functionality may not be as rich as at a traditional site; and capacity may be more dynamic than at a macro cell site.

I do believe that we will see massive scale small cell deployments in the next 24 months. However, I believe it will be absolutely imperative that we first throw out everything we know about traditional mobile network deployment and restart from scratch, with the desired goals of coverage, deployment speed and total cost of ownership clearly defined. From those three critical goals, we will need to reinvent the network deployment process and tools required to deploy a large scale small cell network.

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