FAQs outdoor operations

What do we understand by outdoor wireless LAN?

The term outdoor WLAN includes the following applications:

• Point-to-point directional radio bridges
• Relay operation (to extend wireless bridges)
• Wireless distribution systems (point-to-multipoint connections)
• Campus coverage
• Public wireless LAN Internet access (WLAN hotspots) in outdoor environments

Which access points are best suited for outdoor operations?

If the antenna for outdoor mounting is to be located close to a building, you can optionally use an indoor access point in combination with an outdoor antenna. If this is not an option then the more robust outdoor access points can be used instead. LANCOM outdoor access points (OAPs) are equipped with a protective housing rated to IP 66 or IP 67, depending on the model. The IP-66 rating protects against to dust and water jets; the rating IP-67 means the equipment is resistant to temporary complete immersion. LANCOM OAPs can also be operated in temperatures ranging from -30°C to +70°C. Furthermore the OAP 54-1 Wireless is salt-spray resistant in line with EN60068-2-52, although a plastic housing is to be recommended for permanent installations in salt-water environments (such as in harbors or on ships). The robustness of LANCOM outdoor access points means that they can be mounted outdoors as close as possible to the antenna, so minimizing the performance losses from long stretches of cable.

What improvements does the new 802.11n standard have for outdoor WLAN?

The latest standard improves the ranges and data throughput of point-to-point wireless bridges. With its two connectors for the two integrated antennae, the LANCOM AirLancer Extender O-D9a antenna works with polarization diversity. The simultaneous transmission of horizontally and vertically polarized waves on a single frequency provides two separate transmission paths. As a consequence, point-to-point bridges can benefit fully from the performance gains offered by the 802.11n MIMO technology. Practice has shown that point-to-point connections can benefit from a net data throughput of up to 130 Mbps. More information about 11n and outdoor applications is available in our FAQ on "802.11n for Outdoor Applications".

What main differences are there between the OAP-54-1 and OAP-54?

The OAP-54-1 is equipped with external antenna connectors and also an integrated 2.4- and 5 GHz directional antenna. Unlike the OAP-54 it features just one internal WLAN module. The OAP-54-1 is ideal as a compact, low-cost outdoor solution for scenarios requiring point-to-point bridges or outdoor hotspots. On the other hand, the two internal wireless modules in the OAP-54 provide additional options including relay mode, redundant wireless bridges, or WLAN cells (P2P connection between access points in the 5-GHz band, wireless LAN cell at 2.4 GHz).

Can the OAP-54-1 be combined with external antennae? If so, which ones?

The OAP-54-1 features two external antenna connectors in addition to its integrated directional antenna. The package is shipped with two 3-dB dual-band dipole antennae which are ideal for outdoor public wireless LAN access, for example. The device switches automatically between the internal directional antenna and any connected external antenna by means of a mechanical RF switch in the antenna socket. All LANCOM AirLancer Extender outdoor antennae can be operated with the OAP-54-1. Particularly well suited are:

Note:Note: For an initial estimation of the ranges and data rates available with certain antennae, use the free Antenna Distance Calculator available from www.lancom.eu.

How much transmission power is lost between an access point and an external antenna?

Every connector, cable and surge-protection adapter causes the transmitted signal to be attenuated. The cable connection between the access point and external antenna should be as short as possible. In good condition, a cable connector and surge-protection adapter will attenuate the signal by about 1 dB. Depending on the frequency and cable quality, an antenna cable causes attenuation of about 0.5 to 1 dB per meter. The best results are achieved with outdoor access points with integrated antennae. When using access points with external antennae, other factors may play a significant role such as how the cable reacts to the cable run (flexibility, bend radius). LANCOM AirLancer Extender antenna cables are suitable for 2.4 and 5 GHz, have an attenuation of between 0.5 and 0.6 dB per meter and are easy to install thanks to a high degree of flexibility.

What advantages does the Bridge Kit offer?

Purchasing a Bridge Kit ensures that you have everything you need for your outdoor point-to-point wireless bridge:

• Two OAP-54-1's with integrated directional antennae
• Two UV-resistant Ethernet PoE cables with water-resistant connectors, each 15m long
• Two AirLancer Extender SA-LAN surge-protection adapters for LAN cable
• Two PoE Injectors as power supplies (max. 100m distance)
• Compete mounting kit for mast and wall mounting
• Mounting instructions
• CD with firmware and management software (incl. P2P link monitor)

Available for free download are the LANCOM Antenna Distance Calculator and the LANCOM Outdoor Guide with a great deal of useful information including the appropriate measures for lightning and surge protection.