How many calls can an enterprise femtocell support?

Well the answer to this question comes from the basic definition of a femtocell. It's an obvious answer but it's not necessarily an obvious path to get there.

A femtocell is a mass market device capable of being installed by the end user whether at home or in an office. So in an enterprise this could be the IT department, an IT reseller or one of the mobile operator's other sales channels.

This means that radio planning has to be automated (self-organising or cognitive radio). Assuming femtocells have to co-exist with existing macro networks that cannot be re-planned, what governs a femtocell's power output is the maximum interference the mobile operator will allow. This dictates the maximum power which in turn dictates a trade off between coverage and number of calls supported by each femtocell. Once you know what an enterprise's needs are (building type, coverage and type of business - call density), then it is simple to work out how many femtocells you need to cover the building(s) and what call capacity is needed for each.

So to meet any business's needs you need flexibility and that's why we came up with the concept of meshed femtocell networks. This can be made up of femtocells with various call capacities as needed. You can easily position them around a building so that coverage is guaranteed, as is handover and call capacity, at the lowest possible total cost.

What is an enterprise femtocell?

There has been a lot of debate recently about enterprise femtocells. What are they?

Are they the larger cousins of consumer femtocells, only with more users and more power? But how many users and how much power? Or are they standard consumer femtocells, arranged in a self-managing grid? But what is a standard consumer femtocell?

The problem is that this is a circular debate - there is no single answer, because the wrong questions are being asked. The fact is that the enterprise femtocell simply cannot be defined as a single device specification. Because no two enterprises are the same.

Instead, I think of Enterprise as an application of femtocells. What is important is meeting the individual enterprise's needs and giving mobile operators the flexibility to do this at the right price.

After all, femtocells come in all shapes and sizes, just like places of work. So it would be very efficient to deploy a mixture of 4, 8 and 16-call femtocells arranged in a grid. In other buildings single femotcells of various capacities might be best. I'll explain more another day.

Whatever their capacity, however they are arranged, they are all femtocells. Self-organising, self-managing, low-cost devices that businesses can install themselves.

That should be something we can all agree on.