Product spotlight: CONNECT - Saving OPEX, using adaptive modulation

Next generation networks are fast becoming a reality. WiMAX and LTE are on our doorstep, promising to provide us with the ultimate ‘anytime, anywhere’ broadband experience. Mobile multimedia revolution, rather than evolution, is ready to rule. But we are not there yet. Mobile operators need to protect their profitability, ensuring financially viable next generation networking.

The explosion in the usage of the mobile internet means that the volume of data travelling over the whole network will reach unprecedented levels. This is not an issue in the core part of the network, where optical fibers can transport huge amount of information, but what about the network edges? Let’s take a look…

The current infrastructure to connect the core network to the base stations (backhaul) is mainly based on E1/T1 lines and microwave links. The increase of capacity over the T1/E1 lines translates to a tremendous increase in operators’ OPEX. Therefore, microwave links are a much more cost effective and efficient means to providing a transport network. Another efficient alternative would be transporting via optical fibers, but unfortunately, digging up half the world to install fibers is not especially feasible, even if they do offer optimum capacity.

Backhaul transmission needs to evolve to cope with the future demands of next generation networks. One ingenious new trend that addresses this is adaptive modulation (AM) in microwave networks, where the modulation order of the radio changes according to the link characteristics. In modulation, the data message is transferred over a radio signal. In order to be more efficient, we can transfer more bits at a time, considerably increasing the total amount of data transmitted at a minimal cost. And this is the key point of success for adaptive modulation; delivering more data with less money.

AIRCOM’s CONNECT microwave backhaul and transmission planning tool understands the importance of adaptive modulation and we have introduced it as one of the tool’s core features. The available schemes that the equipment operates on are defined, as well as the required throughput that needs to be delivered. By adapting the right modulation scheme for continuously varying throughput requirements, based on the operating bandwidth for all links operating in the network, CONNECT ensures that it always fulfils users needs. The average throughput is a linear function of bandwidth and operating modulation scheme. The higher the bandwidth, the higher the spectrum costs.

Just work out a cost calculator for yourself in terms of spectrum - by managing the modulation alone based on throughput requirements dynamically, you will start to realize the amount of savings on licensing costs of the spectrum. This in many cases is will be in the order of $1M when managed effectively.

Mobile operators need to make the most out of their investment in their existing infrastructure (TDM and not all-IP), so they will be reluctant to dismiss it all overnight. And that is not all; higher order modulation schemes (256QAM compared to 8PSK) mean that links would be unavailable more often, which it is not a major problem for internet browsing, but would prove catastrophic for voice calls.

Envisioning such needs, and looking towards tomorrow’s technology today, CONNECT provides all the necessary information to a planner, enabling them to make better use of their resources, have a better understanding of their needs and to have a more control over required spending, while maintaining the required Quality of Service. In this business, that balance of control and quality is vital.

JR & AS, CONNECT product team.