2,4 GhZ or 5 GhZ

Choosing 2.4 GHz or 5 GHz

Please check the outdoor WLAN frequencies. The 11Mbps WLAN standard that operates in the 2.4GHz using DSSS modulation. 2.4GHz frequency band is more crowded and more prone to interference. However, 2.4GHz can also deliver much further distance at the same output power comparing to 5GHz device. If your distance requirement exceeds 10/15 Km or if you have operate 2.4GHz WLAN in a heavy interference area, we recommend using the 802.11b solution. The 54Mbps WLAN standard that operates in the 2.4GHz using OFDM modulation. Although the 802.11g provides the ideal solution for indoor WLAN, there is one important feature to take notice for outdoor applications. If you want to reach more than 800 meter using the 54Mbps mode, please make sure your AP supports adjustable ACK Timeout function. 802.11g devices can also operate in the 802.11b mode. The 54Mbps WLAN standard that operates in the 5GHz using OFDM modulation. The 5GHz frequency band is not a crowded as the 2.4GHz band. In addition, the 802.11a have 12 non-overlapping channels, comparing to 802.11b/g's 3 non-overlapping channels. However, the 5GHz device delivers far shorter distance at the same output power when comparing to 802.11b/g. But if higher gain antennas are used, the 802.11a can actually reach higher throughput at longer distance than 802.11g, not than 802.11b ! It is recommended to use this solution if you require higher speed at distance greater than 10 Km. Outdoor WLAN Standards Operating Frequency Advantage Disadvantage Note 802.11b 2.4 GHz Better long distancestability, Less prone to interference than 802.11g. Only 11Mbps Speed. 802.11g 2.4 GHz 54 Mbps Speed at 2.4 GHz band. More prone to interference. Less suitable for distance longer than 10 Km. Can also operate in 802.11b mode. ACK Timeout adjustment required for long distance. 802.11a 5 GHz 54 Mbps Speed at the quieter 5GHz band. Higher throughput at longer distance. Shorter distance than 2.4GHz at the same output power. ACK Timeout adjustment required for long distance. http://www.worldnet.ro/P_AirLive_Documentatie_03.htm

Step 3: Choosing the Right Antennas

A High Gain antenna does not actually increase the output power, but focusing available power at particular direction. For Outdoor application, thereare generally 2 types of antennas. Directional Antennas have limited angles of field in both horizontal and vertical direction. because they do not have to cover 360 horizontal degrees like Omni antennas, directional antennas can have higher gain and wider vertical coverage. Directional antennas are available in Patch, Parabolic, Grid, Yagi or Sector designs. Outdoor Omni Antennas provides a near 360 - degree horizontal coverage. However, the vertical coverage angles are typically much narrower than directional antennas. As a result, omni antennasare more suitable for environments that are roughly at the same heigh to each other. Omni antenna higher than 12 dBi are not recommended due to their very narrow horizontal angle, instead is better than it to be use multiple sectors. Higher Gain isn't always better: If the distance between 2 stations is relatively short and over-powering Ap/antenna combination is used, it can iduce severe performance lost due to Near-Field-Effect. In addition, higher gain also means narrower degree of field. Wider Angle isn't always better: An antenna with narrower degree is more difficult to gain, but receive less noise from outside. This is particularity important for Point-to-Point installation. In an outdoor connection, 2 remotes sites noy only have to be in the line-of-sight, but obstacles in the First-Fresnel Zone can also reduce the performance. A wider angle of field increases the angle of the First fresnel Zone. device & antenna calculator formula »

Step 4: Choosing the Right Cables

When the RF signal travel across an antenna cable, there is always a sinificant amount of cable loss. Therefore, the final output level of an AP/Bridge/Client is influenced greatly by the length and quality of antenna cables. depending on your budget, a high quality cable is also significantly more expensive. Cable Type Cable loss (dB/meter) OEM RLA-10 0.22 Belden H1000 0.22 Cavel RG-213 0.37 Belden H155 0.5 Times LMR-195 0.5 Andrew CN-195 0.5 OEM LX-195 0.65 OEM RG-58 1-1.5