Reader Forum: Executing a small cell deployment with minimal headache

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As smartphones have proliferated, small cells have emerged as a low power option to deal with the overloaded network. They’re especially popular in areas where coverage or capacity is limited, such as homes, rural areas, crowded apartment buildings and busy public spaces. Over the last two years, commercial deployments of LTE small cells have accelerated, bringing small cells out of the living room and into the public arena. Now, we find small cells everywhere: the airport, the mall, hotels, as well as in our homes and offices.
New vendors are jumping on this trend, joining the “base station-on-chip” market. We entered the space at the start or 2011 when we announced QorIQ Qonverge at Mobile World Congress and now we have more than 50 customers with residential, enterprise and metro implementations. Our silicon and software is commercially deployed in Japan, China, the United States and Europe with trials in Latin America and India. We are often asked what we’ve learned while blazing the trail. We shared some of these lessons at Small Cells Americas in December, but here’s a recap of some key areas to keep in mind when looking at commercial small cell deployments.
1. It’s all about the software: Silicon vendors always talk about software, but they usually mean a basic operating systems and board support packages, consisting of a few drivers and perhaps some reference applications. With a small cell deployment, a full-scale, commercial-ready, working application is critical, specifically the Layer 1 PHY, which is closely coupled to the silicon hardware and accelerators. We worked closely with our customers and partners to deliver robust and fully featured solutions and learned a lot in the process, especially the difference between being able to demonstrate capability and having a hardened commercial solution. We also learned that every customer/operator engagement is slightly different and as a silicon partner we needed to be both flexible and nimble. We have seen several companies fall by the wayside trying to meet this new silicon vendor paradigm while at the same time we now have many more resources focused on the software rather than the silicon. The result is a tried-and-true, fully tested software solution that makes a small cell deployment a much less daunting proposal.
2. Flexible hardware options are key: The small cell market is still maturing, and our customers often find their use case changing once they get into the field, and realize during trials that their requirements have shifted. We recently worked with one large customer looking to deploy small cells for rural coverage over a large geographic area. Because of the vast area involved and some of the unique issues that result, they discovered the first product they had chosen didn’t meet their needs and migrated to one of our other SoC solutions. Use cases for small cells and heterogeneous networks are in a state of constant flux, so it makes sense to pick a vendor who has scalable options which will let you leverage your software investment.
3. The growing importance of security at the edge of the network: When small cells are brought into public areas and even private residences, they are by definition less secure than when they are in central offices or secure macro cell sites. This leaves them open to being hacked or physically tampered with. There have been documented hacking incidents where access has been gained to the network, allowing for fraud, denial of service attacks or other malicious activities. For these reasons, it’s important to ensure that your small cell incorporates a trusted compute architecture. In today’s world of distributed connectivity, this is no longer a “nice to have,” but rather a mandatory feature. Such architectures provide detection of denial of service and other attacks, built-in hard and soft security protocols can sense and deal with attacks, putting the cell back into a secure mode. Trusted compute architectures have tamper detection circuitry, flagging irregular traffic patterns and physical attacks via secure interrupt handling, alerting software to take action to correct the problem, by shutting down, resetting or sending an error report.
4. Hetnets need organizing: As small cells become less of a band-aid for network coverage and are increasingly part of a strategic deployment plan, network operators must balance and manage a large numbers of small cells. This starts with small cells that are self-deployable, initializing and registering themselves on the network, and ends with system-level inter-cell interference coordination and network load balancing. If small cells are to be successfully deployed widely, then the average consumer must be able to deploy them at home. In other words, plug and play – where the cell can register itself, check for other cells that are transmitting nearby and synchronize to the network. The real benefits of SON are in the network core but if they are to be realized then a robust network listening mode needs to be encompassed in the femto PHY to pass the MIB and SIB data back to the higher level software. Another software requirement for silicon vendors.
Commercial small cell deployments can be complicated to execute, but with a little foresight and planning, they can be a key tool for operators to provide cost effective coverage and capacity. The key is to select the right partner who can provide scalable solutions, robust, commercial grade PHY and NLM software and the right level of security at the edge of the network.