Things from the Edge of the Wireless Envelope

May 21, 2014

By Ernest Worthman

Today’s wireless world is changing so fast that the people who say it can’t be done are often interrupted by those that are already doing it. The author is unknown but how true that statement is. And PCIA is right there, bringing proof of that to you. Not just at trade shows, but on a daily basis, all year, and almost every day.

The Wireless Infrastructure Show brings new and innovative offerings from cutting-edge players that are conquering the challenges that small cells deployments face. Tuesday’s sessions ranged from edge-of-the-envelope technological presentations to reality checks on the legal landscape.

Technology update

One session that was particularly well attended discussed one of the most pressing concerns of small cell deployments – backhaul.

Backhaul has several issues, but one of the most complex is power. It is easy to drop a small cell just about anywhere, but getting it to power up can be more challenging. Small cell deployments near established power infrastructures don’t present much of a problem. It is the remote locations that do.

It would seem simple just to run power and backhaul systems from a remote site back to the power and distribution system. However, there are a number of factors that complicate it, especially if a considerable distance is involved.

Setting aside the regulatory issues such as electrical regulations as set forth by the NEC, and local codes, deciding how to power remote nodes is multifaceted. For example, power cable metrics over distance, backup power requirements, types of power available (supplied vs. local, i.e., solar or wind) are all design criterion that are part of the equation. As well, capex and opex need to be considered, as does maintenance and technical support.

The biggest issue is keeping the remote site up – how much redundancy should be built into the site to make it always on. That essentially translates into battery backup. The session had a much focused segment that discussed battery and battery technology. Great stuff if you are involved in remote small deployments and certainly one of the highlights of this session.

Another highlight of this session was the discussion on hybrid cable. The panelists did an outstanding job covering the technical aspects of fiber/copper hybrid cables and the advantages and problems one can bump up against when deploying it.

On the non-technical front there was a session on property logistics and small cell deployments. It was a round table discussion where the panelists answered question about where to put small cells and how to go about getting them placed.

Interestingly, three basic issues surfaced in when deploying small cells – location, power and backhaul. The panel brought up issues such as just because you want a small cell there doesn’t mean it will work out that way. And even in a small cell location is acceptable, power and backhaul have to be available or, able to be made available.

The panelists also discussed a major hot button – zoning. A reality check is that placing a small cell can be just about as complex as a macro cell. There is a great deal of coordination that must take place, especially if the cell is going to be on utility or railway property, which is often a desired situation. In many cases, negotiating the placement of a small cell involves contract law and complex legal documents around rights of way, and adjacent property effects. Overall a bit of an eye opener to the logistics that can impede or complicate small cell deployments.

Finally, one of the more lively panels revolved around the future of macro sites against the backdrop of the predicted one million small cells expected to be deployed by the end of 2016.

There were some interesting arguments from panelists with macro site interests, and they made some valid points. For example, where is the tipping point regarding a single macro site vs. a number of small cells? A complex topic since costs vary for each due to a multitude of factors. But the fact remains that in some cases, the cost of a macro site can be less that the equivalent group of small cell for the same coverage metric.

As well, panelists discussed the option of upgrading a macro site with cutting edge technology, such as agile antennas, sectorizing, power control, and tighter, more precise transmission envelopes, to solve coverage and loading issues. This, as opposed to deploying small cells to resolve these issues.

They also discussed how new technologies, such as LTE and LTE-A can up the performance ante of macro sites. Again, in lieu of off-load to small cells.

Finally, the opex/capex discussion reared its ugly head. It may be cheaper to deploy a series of small cells initially, but what will be the amortization metric over the long run? Would it be more cost effective than a new/upgrade macro site?

Over all a good, though provoking discussion addressing the angle that the macro infrastructure is built out, and small cells are the deployment platform of the future.