Wavion’s Interference Immunity Suite

Wavion’s Base Stations are designed from the bottom up for the outdoor environment. Unlike all the other competing products, they are based on a proprietary ASIC designed specifically by Wavion for the challenging outdoor environment. This ASIC and the supporting HW and SW incorporate several critical capabilities to mitigate the interference. The key capabilities are:

  • TX and RX (two-way) Beamforming
  • Dynamic Interference Handling (DIH)
  • Wavion Rate Adaptation (WARA)
  • Automatic Channel Selection (ACS)
  • Down Tilted Antennas (DTA)

Two-way Beamforming

The Beamforming focuses the energy to and from a user per packet by assuring that the signals in all the different propagation paths combine coherently at the user location on Tx, and at the base station modem on Rx. The Beamforming ability to exploit multi-path, rather than suffer from it, significantly enhances the base station’s coverage and quality, especially in NLOS conditions, wherein it eliminates dead spots and assures homogenous coverage. The Beamforming further provides significant interference resilience, due to the inherent beam directivity which suppresses the interferences. More specifically, by forming a beam towards a user location, all the interferences from other locations are suppressed by an average of 5 dB. This is a critical benefit of Beamforming that helps Wavion’s base stations to overcome interferences. Similarly, the same level of 5 dB suppression is achieved on Tx, thus reducing the self-interference of adjacent base stations to each other.


Dynamic Interference Handling (DIH)

The WiFi protocol is based on the CSMA/CA mechanism that requires that the air be sensed before each packet transmission to avoid collision. In the case of heavy interfered environment, the air may be congested and prevent any transmission if the system parameters are not optimized properly.

Wavion’s Dynamic interference handling (DIH) capability was specially designed for heavy interfered environments. It constantly monitors the environmental noise and interference levels and based on a proprietary algorithm optimally sets the air-access thresholds and the system parameters so as to optimize the base station’s performance.

Wavion Rate Adaptation (WARA)

The rate (modulation) should be employed for each packet transmission should be ideally selected according to the signal-to-noise ratio existing at the time of transmission. If the signal-to-noise is low, a low rate (modulation) should be selected since low rates are more immune to noise. Conversely, if the signal-to-noise is high, a high rate (modulation) shall be selected enabling higher data speeds. This implies that for optimal rate selection one has to monitor the signal-to-noise level. Yet, the noise level in outdoor deployments changes rapidly and unpredictably. Moreover, it is characterized by high level bursts of interference coming from WiFi and non-WiFI signals, making the rate selection a much more challenging task. Specifically, in case of strong bursty interference, it may be counter-productive to select a low-rate modulation. Indeed, in this case, a low rate implies a long packet duration, which in turn implies a higher probability to be hit by the interfering signal. In this case it is better to be aggressive and select as a high rate as possible since a shorter packet have a lower probability to be hit by the interfering signal. Wavion’s rate selection process, referred to as rate adaptation, was specifically designed to cope with the high interference level in the outdoor environments and it optimally selecting the best rate according to the noise and interference levels, assuring the optimal performance of the base station.

Automatic Channel Selection (ACS)

The level of interference and activity in the WiFi spectrum varies as function of location, frequency and time. It is therefore critical that each base station will select the WiFi channel with the lowest activity level and interference level to assure the best possible performance. Wavion’s Automatic Channel Selection (ACS) capability was specially designed to meet this challenge. It scans all the potential WiFi channels and measures both the interference level and the activity level at each channel. This can be done offline or online, while in normal operation and with negligible effect on performances. Then, using a proprietary algorithm, it selects the “cleanest” channel for operation, assuring the optimal performance of the base station.

Down Tilted Antennas (DTA)

In case the base stations are installed on high towers or high roof-tops, the signals to and from the users are impinging the base station at high elevation angles. In this case it is preferable to tilt the antenna beam so as to assure that the users are well covered. This tilting also significantly reduces the level of interference since most of the interfering sources are impinging from the horizon and thus will be suppressed by a tilted beam. Wavion enables this beam tilting both in its Omni base stations, by a proper design of its omni-directional antennas, and in its Sector base stations, by allowing simple and flexible mechanical tilting.