The dramatic shift to remote radio heads (RRH) with third and fourth generation cellular mobile technologies has created a real disconnect from the past when it comes to connectivity on cellular sites.
First and second generation cellular mobile technologies were mostly installed using traditional site architecture with the radio housed within a shelter or cabinet at the base of a tower and connected to the antenna at the top of the tower using coaxial cable. This was a well established and understood practice, the interfaces were standardised, the cable sizes were well defined in relation to the tower height and installation practices had evolved over many years to become common practice.
Now with the proliferation of remote radio heads the interconnection between the bottom of the tower and the top is a brave new world for those that have been installing cellular systems for the past twenty years. Gone is the co-axial feeder cable that we are all so familiar with, and in its place the installer now needs to install power cables and optical fibre cables between the baseband equipment at the bottom of the tower and the radio at the top. But which fibre cable? What size power cable? Terminated on site or pre-terminated? It seems every radio manufacturer has their own specification on what fibre cable and what conductor sizes should be used and what interfaces will be used and how it should be done. In addition every wireless operator has their preferences as well.
Radios have migrated to the top of the tower in part to improve the efficiency of power consumption on site, no longer is power wasted on air-conditioning in equipment shelters or lost in co-axial feeder cables. The flipside is that radios are no longer easily accessible for maintenance and repair and as such a lot of effort has gone into making remote radio heads as reliable as possible to avoid the complication of replacing them if they fail.
If an operator has gone to the expense and effort of putting their high reliability radios on top of the tower the last thing they want to do is use an unreliable or vulnerable solution to connect to it. That is why although the simplest way to make the interconnection is to use separate fibre and power cables, an operator with reliability of their network in mind would insist upon the vulnerable fibre and power cables being housed within a conduit to protect them from damage from rodents, birds and even stray installers boots.
With the growing demand for more data, more bandwidth and more services, many operators are installing multiple RRHs on a tower to cover multiple frequencies and technologies. In addition they can already see the need to add further RRHs in the future as more spectrum becomes available to them. It can be a costly exercise to add new cables to a tower and may require the hire of equipment such as a cherry picker. If a trunk fibre and power cable that can cover both today’s needs as well as the future requirements can be installed now, it will save the operator expense and problems when they add their future services.
Imagine a trunk cable that has sufficient conductors and fibres to cater for the requirements of both today and tomorrow? What if that same cable could was armored to protect against rodents, birds and installation mishaps?
And finally what if that cable could accommodate a range of manufacturers current RRHs as well as changes to new and different RRHs in the future?
Wouldn’t that interconnection solution that will cater for future requirements as well as simplifying your installation on site today be something worth investing in?
Have you thought about your strategy and how you can proceed with network modernisation?
Our vice president of strategic marketing, Philip Sorrells, will be speaking at the upcoming LTE Asia event in Singapore on 18th and 19th of September about this and other practical considerations for network modernisation and optimisation with LTE.