(ii) High Transmission Power And High Gain Directional Antenna Comparatively, Outdoor CPEs are designed with higher maximum transmit EIRP. Greenpacket OX series Outdoor CPE has a 14dBi antenna, Dual transmitters (2Tx) with a combined Tx power rated at 27dBm, thus a maximum transmit EIRP equivalent to 41dBm, making it the most powerful mobile WiMAX CPE in the market today. Directional antenna is conventionally implemented to optimize the antenna performance specifically aligned to face towards the base station. Different from an indoor or USB based device, operator will normally assign service engineers to the premise where installation is based on the optimum facing direction and upon locating it, the outdoor antenna is locked into place. Figure 3 shows a sample antenna pattern for the 2.5GHz model. The diagram shows a concentrated RF energy radiated in a single direction (+- 10 degrees within the pink line). This specific radiation pattern plays the highest role of effectively increasing the coverage area.
Figure 3: Antenna patterns for OX250 main antenna
5dB improvement
USB dongles Average 23dBm 2dBi Antenna
11dB improvement
Indoor CPE Average 25dBm 5dBi Antenna
Outdooe CPE (OX series) Average 27dBm (2Ti) 14dBi Antenna
Figure 4 : Improvements of Outdoor CPE over indoor CPE. We can see that OX series can have 16dB improvements from indoor USB dongles
APPLICATION NOTE
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