Based on a solution introduced by Alvarion, today’s SU-MIMO and MU-MIMO services have become an integral part of Wi-Fi WAVE-2 802.11ac and cellular LTE rel 11 protocols. Designed by Mati Wax – Alvarion’s Chief Scientist – beam forming technologies enhance Wi-Fi connectivity by providing improved and continuous bandwidth over a greater distance while maintaining lower emissions on access points.
Directional Beam Forming Technology
Access points generally use a radial antenna to evenly transmit energy to their surrounding circles. The size of a circle depends on the strength of its power supply which is regulated whereby preventing interference with other systems transmitting nearby and safeguarding public health. Since each access point transmits an equal but limited amount of energy within its circle, a lot of energy is wasted and there is no transmission outside a circle.
Over the years it has been understood that a signal can be made stronger and more directional using multiple antennas for its transmission. In other words, using multiple antennas enables focusing on specific or multiple locations to reach a greater distance to provide a stronger signal than a standard radial antenna. By conserving resources, the same amount of energy reaches more stations positioned further away from their access points bringing more services and greater bandwidth.
Pioneers of Change
One major problem faced by Mati’s team was to identify the exact position of each endpoint communicating with each access point. Their answer was to increase the size of the circle by placing multiple antennas on an access point where each antenna was set at a different angle. The data collected from each antenna was used to create a map of all endpoints. The result was a matrix the size of the number of endpoints used. Each new signal per antenna was transmitted by multiplying all the needed signals with the matrix coefficients per antenna. Each endpoint received input from all antennas which when combined together as a wave transmitted the original signal to the endpoint.
Years later, the team’s pioneering research became the foundations of today’s MU-MIMO Wi-Fi and LTE protocols which automatically report the exact location of each end point communicating with an access point.
A Best Seller Also Today
By increasing Wi-Fi bandwidth capacity, beam forming has become a standard in the Wi-Fi connectivity arena. Today there are still endpoints that do not comply with latest Wi-Fi standards. Employing Mati’s technologies, Alvarion WBS access points efficiently communicate with all endpoints to provide greater capacity.