ORiNOCO AP-4000/ 700 Antenna Diversity

DESCRIPTION

General and Internal Antennas

Each radio on the AP-4000/ 700 employs two internal antennas for antenna diversity: one is vertically polarized, and the other is horizontally polarized to provide optimal spatial and polarization diversity. When the AP is hung on the wall of an office or building, the horizontally polarized antenna provides coverage for that particular floor level. The vertically polarized antenna provides spatial diversity for the horizontally polarized antenna in the event of an antenna null. In addition, the vertically polarized antenna provides some coverage above and below the current floor level. When the AP is mounted on the ceiling or sitting on a table, the effect is the same, but the roles of the two antennas switch.

The AP supports both receive and transmit diversity. When receiving, the AP chooses the antenna that receives the strongest signal. When transmitting, the AP chooses the antenna with the highest success rate, and broadcasts are transmitted on alternating antennas.

Antenna diversity is enabled by default (set to “auto”) per wireless interface. When using the internal antennas, Proxim recommends leaving antenna diversity enabled. However, you may disable antenna diversity by manually selecting which antenna to use for each wireless interface through the Command Line Interface. See Configure for this information.

External Antennas on an AP-4000

The AP-4000 also has four antenna connectors, two on each radio, for use with external antennas. External antennas can be used with either radio on the AP-4000.

AP-4000 Image

Connectors 1 and 2 are for the 802.11b/g radio; connectors 3 and 4 are for the 802.11a radio. When the AP is mounted on a wall, connectors 1 and 4 correspond to the horizontally polarized internal antenna, providing a coverage pattern parallel to the wall; connectors 2 and 3 correspond to the vertically polarized internal antenna, providing a coverage pattern parallel to the ceiling/floor. When the AP is mounted to a ceiling, connectors 1 and 4 correspond to the vertically polarized internal antenna, and connectors 2 and 3 correspond to the horizontally polarized internal antenna. Plugging an external antenna in to the antenna connector disables the corresponding internal antenna on the wireless interface.

The AP continues to support antenna diversity with external antennas connected. With one external antenna connected to one of the two antenna connectors on a radio, one internal antenna and one external antenna are used for antenna diversity. With two external antennas connected, both external antennas are used for antenna diversity, and both internal antennas are disabled.

With external antennas connected, you may wish to manually select a particular antenna for use. To do so, disable antenna diversity by manually selecting which antenna to use for each wireless interface through the Command Line Interface.

External Antennas on an AP-700

The AP-700 also has two antenna connectors for use with external antennas.

AP-700 Image

When the AP is mounted on a wall, connector 1 corresponds to the horizontally polarized internal antenna, providing a coverage pattern parallel to the wall; connector 2 corresponds to the vertically polarized internal antenna, providing a coverage pattern parallel to the ceiling/floor. When the AP is mounted to a ceiling, connector 1 corresponds to the vertically polarized internal antenna, and connector 2 corresponds to the horizontally polarized internal antenna. Plugging an external antenna in to the antenna connector disables the corresponding internal antenna.

The AP continues to support antenna diversity with external antennas connected. With one external antenna connected to one of the two antenna connectors, one internal antenna and one external antenna are used for antenna diversity. With two external antennas connected, both external antennas are used for antenna diversity, and both internal antennas are disabled.

With external antennas connected, you may wish to manually select a particular antenna for use. To do so, disable antenna diversity by manually selecting which antenna to use through the Command Line Interface.

Note: Using two external antennas is not recommended, since spatial and polarization diversity is based on distance, positioning, and location of the internal antennas. The addition of external antennas that have not been designed for this diversity will not only disrupt diversity but may lead to the possibility of antenna interference.

For a list of recommended antennas for the AP-4000 and AP-700, click here.

CONFIGURE

The following commands via the CLI are for enabling or disabling antenna diversity on an AP-4000:

[device-name] set wif 3 atdiversity <3, 4, 5(auto)>

[device-name] set wif 4 atdiversity <1, 2, 5(auto)>

[device-name] reboot

Explanation wif

3 = 802.11a

4 = 802.11b/g

Explanation atdiversity (connector numbers as shown in the above AP-4000 Image)

Connector 1 = 802.11b/g

Connector 2 = 802.11b/g 

Connector 3 = 802.11a 

Connector 4 = 802.11a

5 = auto; will enable both antenna ports for the corresponding interface

The following commands via the CLI are for enabling or disabling antenna diversity on an AP-700:

[device-name] set wif 3 atdiversity <3, 4, 5(auto)>*

[device-name] reboot <between 0 and 65535>

Explanation atdiversity (connector numbers as shown in the above AP-700 Image)

Connector 3  = 802.11a/b/g

Connector 4 = 802.11a/b/g