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J-Series Data Radio – User Manual
Issue 09-10
Point to Point with LinkXtend™ Bridge (PTP/B)
The typical range of the Point to Point (PTP) Network Type can be extended using the Trio Datacom unique dual antenna LinkXtend™ technology.
This is achieved using a special radio mode called BRIDGING. A dual antenna LinkXtend™ bridge allows the maximum range possible from a
single radio store and forward technology whilst remaining within legal antenna EIRP limits. A typical Point to Point with Bridge network is shown
below.
The Point to Point with LinkXtend™ Bridge (PTP/B) type of network requires one Access Point, one or more Bridges and one Remote radio. The
Bridge operates in two different modes which alternate depending on what hop (odd or even) the hopping pattern is currently on.
During even numbered hops, the Bridge functions as a Remote to the network Access Point. Using the location of the Bridge in the network as a
reference point, any data sent from the Bridge to the Access Point is sent “Upstream”.
During odd numbered hops, the Bridge functions as an Access Point for the Remote radio. Using the location of the Bridge in the network as a
reference point, any data sent from the Bridge to the Remote is sent “Downstream”.
Thus a Bridge is a radio which functions both as a REMOTE and an Access Point in a time division multiplexed network.
When implementing this network it is important that the NETWORK TYPE is selected as Point to Point via Bridge (PTMP/B). This ensures the
network is divided up into multiple Sub-nets that supports the time division multiplexing of the system required by the Bridge. Each Sub-Net uses a
completely different hopping pattern so that multiple Bridges in the network will not interfere with each other.
Access Point to Bridge communication occurs on one Sub-Net whilst Bridge to Remote communication occurs on another Sub-Net. The Access
Point radio is responsible for network timing so that the Bridge is always operating in the correct mode ensuring data is not lost due to collisions
between Access Point and Remote.
Each additional bridge in the network requires the definition of a new Sub-net. For more information on Sub-Nets, refer to Section D of this user
manual. Network latency is doubled when compared to the latency of a network without bridges but due to the high speed nature of the J-Series
family, network latency is seldom an issue.
When Bridge mode is selected the radio can be configured for either a single antenna or dual antenna. Only on sites that require dual antenna
LinkXtend™ technology does a bridge need to operate in dual antenna mode. There are no limits to the number of bridges allowed in any one
network but additional Bridges will result in extra latency due to the time taken to transport data through the bridge.
It is recommended that omnidirectional and yagi antennas are used for BRIDGES (depending on network design) and directional yagi antennas are
used for Access Point and REMOTE radio sites as this will provide maximum system gain legally allowed. However, some sites where Bridges may
be located may not require the use of dual antennas and in these situations a single omnidirectional antenna can be used. For more information the
dual antenna port feature please refer to Part D of this User Manual.
All other aspects of the Point to Point (PTP) network previously mentioned apply to this type of network.
Part C – Network Types
Содержание JR240
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