Future of Wireless xG

 The future is wireless and the future is mobile.   Many say we are at the start of a revolution initiated by the smart phones.  Connecting cars, connecting clothes, health, wealth, social media, etc..

All of the above will continue to put strain on the wireless networks.   We are rolling out 4G yet we are already looking at 5G.   The demand for capacity will only increase, not only that we want service everywhere.

In designing a wireless network, one of the issues you have is getting indoor coverage.  The cost involved in getting indoor coverage is huge.   To give you an example, to cover a radius of 2 miles using LTE (12sq miles) for outdoor coverage you can do with one tower.   To get indoor coverage you are looking at at least 12 tower sites.

That is because to get inside a building, a typical home you could loose up to 30db, depending on how many walls, roofs etc your having to go through, but even if you lost 12db, you would achieve only half a mile radius.  

There is a second problem linked to the indoor coverage, we hear about LTE giving us 150mb and LTE-A achieving +1Gb, but when the network operators deploy their networks they never achieve anything close to that.

The large speeds obtained are for optimum operating conditions and reality the operating conditions come no where close to optimum and hence the radios cannot operate at the higher modulation rates or make use of the MIMO, resulting in much lower speeds.  

One of the reason this is the case is because to achieve indoor penetration, you loose a huge amount of link budget and hence when you are inside buildings you are communicating at low rates.  This not only affects your speeds who is inside but the total through put of the base station.  As valuable time resource is being spent serving an indoor customer on a low modulation rate, the outdoor user with a higher link budget also is affected.

The result is that more base stations need to be deployed, or more towers, due to limited frequency and frequency reuse you have to deploy more towers and this starts to get costly.

The question I ask is, imagine you could design a network for just outdoor coverage, you could do that with a fraction of the cost, possibly a tenth of the cost.   Then you put the onus on the customers, to install some form of a repeater in their buildings, which is connected to an outdoor antenna.

So the outdoor antenna has a good link budget and then you use a repeater indoors to distribute the signal, like an extender.   It will need to cover a large band, say 300MHz - 3GHz.

There is cost to the customer but its a one off cost, as long as the repeater is an RF repeater and not one that demodulates and remodulates, then you don't need to change it, it will work in that band regardless of the technology being used.

Who pays ?  Well the customer can pay or the operator can pay.   Lets look at the two models:

1.  Customer pays ?   Why should the customer pay ?  Well the customer should pay because its an investment and gives the customer access to cheaper bandwidth.  Imagine if the operator charges you not only for bandwidth but also time slots that you consume on their network, so that if you were operating at a high modulation rate you would use less time slots to pass the same amount of information.   Now this gives the consumer an incentive to invest in the outdoor unit.

2.  Why should the operator pay ?  Well they could offer cheaper bandwidth to the customers and be more competitive also as they will need less capex to roll out the network they can then invest in the infrastructure at the customers home or buildings.  The building side infrastructure should be a one off cost with a long life expectancy, as its an RF repeater, you can pass wifi, LTE, WiMax etc... you don't need to change them every time you roll out a new technology.   Every time you do roll out a new technology you will have less towers to install the kit on.

If you could select the channels you want to repeat or not, then it could send up a secondary industry for companies to install these on buildings and rent them to operators, and activate different channels for different operators.

It would increase the spectral efficiency and reduce the costs of future bandwidths.