From HetNets to Ultra-Dense Networks – where you’ll never be more than a stone’s throw away from a base station
A couple of years ago, one of the top buzz-words in the telco industry was ‘HetNets’ or Heterogeneous Networks, describing the amalgamation of macro and small cells using all radio access technologies as part of a single, super-network. As HetNet roll-outs have progressed, we don’t seem to hear that term so much these days. Instead, the talk has moved on to Ultra-Dense Networks (UDNs).
A UDN takes network density a leap beyond, with base station and access point sites on every lamp post or within 10m of each other indoors. By 2025 or 2030, UDNs will cover most urban indoor and outdoor areas and provide cell edge data rates of 100 Mbps to everyone.
Obtaining and running such an extreme density of sites without costs spiraling out of control will prove to be a challenge for operators in several ways.
Read our new White Paper for a more in-depth look at the evolution of networks to UDNs.
Also, check our discussion paper that provides an insight into the practical challenges of deploying small cells and how to solve them
Getting the right sites
Firstly, how can you cost-effectively acquire so many sites and assess their suitability for the network? Typically, thousands of potential sites need to be assessed. It’s also likely they will be owned by many different organizations, leading to a potentially huge negotiating workload just to gain access.
One compelling solution is to use a list of sites that have already been pre-qualified and agreed with the owner as suitable for small cell deployment. Another way to make life easier is to share sites with other operators.
Getting the right sites installed
The next consideration is the cost of installing the infrastructure. Applying conventional macro-based routines is simply too costly and too slow.
Cost are cut by selecting compact access point nodes that are simple and fast to mount at a wide range of sites, with fewer skilled staff. Choosing the right network architecture, using e.g. centralized RAN deployment or a controller based UDN, further reduces TCO when tailored to the environment. Further savings are made by clustering small cells for bulk deployment using simultaneous planning and installation, while Intelligent Self-Organizing Network (iSON) capabilities allow configuration to be automated, for faster set-up.
Deployment costs also depend on how easily power and backhaul transmission can be brought to a site. Again, selecting the right products helps, for example base stations that can be daisy-chained together using a building’s shared Ethernet indoors or wireless backhaul to connect nodes in a long avenue. Meanwhile, small cells with relaxed latency requirements enable lower quality, more readily available backhaul connections.
Getting the right sites running
Operating expenses must be kept in check, with energy reduction a key focus area. Techniques such as dormancy features can save significant power by shutting down carriers or switching off MIMO when not needed. Other energy reduction measures include site optimization to reduce RF power on some macro sites; beamforming to improve efficiency by cutting interference; distributed systems with baseband pooling to improve resource use; and network modernization to replace legacy equipment with more efficient modern solutions.
With tens of thousands of sites in use, operators will be seeking new ways to monitor and maintain them. This means moving from conventional reactive (‘break then fix’) network maintenance, to proactive (‘health checking’) maintenance based on analytics, extensive automation and redesigning tasks and processes. Deploying cloud-based radio networks will further improve performance, simplicity and cost of ownership.
All of these issues and more need to be addressed as networks evolve and 5G takes off.
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