Less Interference for More Backhaul Capacity

Donald-Gardner-10-20-14--thumb Donald Gardner September 16, 2015

Sentinel-videoMobile backhaul is an important component of wireless networks and cannot be ignored in the transition from 3G to 4G and soon to 5G. In fact, backhaul is currently one of the biggest investments for carriers. Groundbreaking microwave antenna technology is making it possible for mobile operators to achieve their key performance indicators (KPIs) for backhaul.

CommScope conducted a survey with transmission teams and senior management of global mobile operators, equipment manufacturers and regulatory bodies that established the main challenges facing the mobile backhaul and transmission domain. The survey showed that the main challenges that need to be addressed are:

  • Capacity – the demand for capacity in mobile backhaul and transmission networks is increasing
  • Density – the number of microwave paths per unit area is increasing and, as a result, interference problems are increasing
  • Network quality – the expectations of users for quality of service are increasing
  • Total cost of ownership (TCO) – the pressure to reduce TCO for operators is increasing

Shannon’s Law indicates that the capacity of a channel can be increased by increasing the bandwidth, increasing the signal power and/or reducing the receiver noise. In today’s reality, the challenge is not just capacity but density. Every year, mobile operators go through expansion programs and add more links in their networks, generating another variable (i.e., interference).

The C/I ratio (carrier-to-interference ratio) becomes important during microwave link planning, design and optimization, where sophisticated software is being used to get the maximum performance from backhaul and transmission networks. One of the goals is to maximize C/I ratio, so the available capacity can be increased, hence revenue is maximized.

The C/I can be increased by increasing the carrier power or reducing the interference. You can achieve the former by increasing the transmitted power, but there are often regulatory and interference constraints. Bigger antennas increase the gain; however, they cost more and impact tower loading. You can reduce interference by using a different frequency, but this is not always possible because of finite spectrum. You can use a different transmission path, but this too is not always possible.

CommScope believes the best solution for reducing interference is to use low side lobe microwave antennas called Sentinel. Sentinel microwave antennas offer extremely low side lobe levels to meet European Telecommunications Standards Institute (ETSI) Class 4 standards without compromising the gain of the antennas. Their performance has been validated in two case studies in Hungary and the UK.

Want to learn more? Leave me a comment, and I’ll be happy to answer any questions.

About the Author


Donald Gardner

Donald Gardner is new product development manager within the Microwave Antenna Systems team at CommScope and is based in Kirkcaldy, Scotland. Holding a Master of Engineering degree from the University of Strathclyde and a Master of Business Administration from the University of Edinburgh, he has been involved in the wireless communications industry for over 30 years. Prior to his current position, Gardner held various positions in quality, engineering and product management within our microwave antenna group. His key expertise includes mechanical and process engineering of microwave antennas and product management of microwave backhaul solutions.