摘要:
Embodiments of the invention facilitate providing wireless links with longer link ranges and/or better suppression of interference than can be provided by the integrated antennas of a typical wireless network node. While, in some cases, it is possible to install intermediate wireless network nodes to hop through long expanses between distant wireless network nodes, it is desirable for distantly spaced wireless network nodes to reach one another through a single transit link (i.e. one hop). This approach is preferable because a single transit link is capable of higher data rates and better interference suppression than multi-hop transit links. The present invention provides methods and apparatus for enhancing the link range achievable by typical wireless network nodes so that distantly spaced wireless network nodes are able to communicate with one another using only a single-transit link.
摘要:
Packets in a multi-hop wireless network are routed based on the available link throughputs, network node congestion and the connectivity of the network in a manner that minimizes the use of radio resources and minimizes delay for packets in multi-hop system. The routing method also avoids congestion in the access network, especially near the network access points as provided by network access nodes. Each wireless network node maintains a link table for storing link conditions and associated route costs. Packets are routed according to the low cost route. Subsequent wireless network nodes evaluate whether a lower cost route is available and, if so, route the data packet according to the lower cost route. Every wireless network node transmits the data packet, a specified route and a time stamp indicated a time of the last data entry in the link table that was used to calculate the low cost route.
摘要:
Embodiments of the invention facilitate providing wireless links with longer link ranges and/or better suppression of interference than can be provided by the integrated antennas of a typical wireless network node. While, in some cases, it is possible to install intermediate wireless network nodes to hop through long expanses between distant wireless network nodes, it is desirable for distantly spaced wireless network nodes to reach one another through a single transit link (i.e. one hop). This approach is preferable because a single transit link is capable of higher data rates and better interference suppression than multi-hop transit links. The present invention provides methods and apparatus for enhancing the link range achievable by typical wireless network nodes so that distantly spaced wireless network nodes are able to communicate with one another using only a single transit link.
摘要:
Packets in a multi-hop wireless network are routed based on the available link throughputs, network node congestion and the connectivity of the network in a manner that minimizes the use of radio resources and minimizes delay for packets in multi-hop system. The routing method also avoids congestion in the access network, especially near the network access points as provided by network access nodes. Each wireless network node maintains a link table for storing link conditions and associated route costs. Packets are routed according to the low cost route. Subsequent wireless network nodes evaluate whether a lower cost route is available and, if so, route the data packet according to the lower cost route. Every wireless network node transmits the data packet, a specified route and a time stamp indicated a time of the last data entry in the link table that was used to calculate the low cost route.
摘要:
A wireless network has nodes, which can be accessed by wireless terminals via wireless access links, coupled via wireless transit links using multiple directional antenna beams. The nodes are self-organizing and self-adapting as nodes are added and as other changes occur. A new node uses beam scanning to listen for signals from any existing nodes and responds accordingly to join a network. Established nodes each recurrently transmit a welcome message on unused beams, to be received by a new node. Failure of transit links, e.g. due to interference on a channel frequency, is detected with automatic restoration using another frequency. Beam scanning can be enhanced using alternate overlapping beams and diversity techniques.
摘要:
Systems and methods of coordinating transit links between network nodes in a wireless communication network are disclosed. Transit links between a network node and respective neighbouring network nodes are monitored for communications control signals from any of the neighbouring network nodes, and a particular transit link is selected for data exchange upon receipt of a communications control signal. Each transit radio link antenna beam at a network node is thereby aligned with a respective neighbouring network node when the neighbouring node sends a communications control signal.
摘要:
A wireless network has nodes, which can be accessed by wireless terminals via wireless access links, coupled via wireless transit links using multiple directional antenna beams. The nodes are self-organizing and self-adapting as nodes are added and as other changes occur. A new node uses beam scanning to listen for signals from any existing nodes and responds accordingly to join a network. Established nodes each recurrently transmit a welcome message on unused beams, to be received by a new node. Failure of transit links, e.g. due to interference on a channel frequency, is detected with automatic restoration using another frequency. Beam scanning can be enhanced using alternate overlapping beams and diversity techniques.
摘要:
A problem with mobile radio systems is the potentially harmful interference they may cause to other electronic equipment. Such interference can be dangerous and even life-threatening in hospitals and aircraft. Interference to automobile electronic braking systems, air bag actuators, or train system controls are examples of other areas where radio system interference must be prevented to preserve the safety of operators and passengers. The present invention provides a system whereby mobile radios, e.g. cellular phones, can be operated safely in regions where interference could cause serious problems or can be prevented from operating. The mobile radios are provided with a low power mode of operation and are commanded, via their signalling channels, to operate in the low power mode when within range of a low power signal from a base station within a protected area. In some areas where it may be undesirable for the mobile radio to operate, even at low power levels, the base station may broadcast an inhibiting signal which will instruct the mobile radio not to operate its transmitter while in the area.
摘要:
Packets in a multi-hop wireless network are routed based on the available link throughputs, network node congestion and the connectivity of the network in a manner that minimizes the use of radio resources and minimizes delay for packets in multi-hop system. The routing method also avoids congestion in the access network, especially near the network access points as provided by network access nodes. Each wireless network node maintains a link table for storing link conditions and associated route costs. Packets are routed according to the low cost route. Subsequent wireless network nodes evaluate whether a lower cost route is available and, if so, route the data packet according to the lower cost route. Every wireless network node transmits the data packet, a specified route and a time stamp indicated a time of the last data entry in the link table that was used to calculate the low cost route.
摘要:
A method of detecting extra-system signals in a multi-node RLAN (radio local area network) involves: at each of a plurality of nodes in the RLAN, processing at least one respective received signal to produce detection results and deciding whether an extra-system signal has or has not been detected based on detection results of at least two of the plurality of nodes. The extra-system signal is for example a signal from a RADAR system. The detection results are produced using pulse pattern matching for example. Furthermore, in some implementations a decision as to whether an extra-system signal has or has not been detected is based on a comparison of a detection signature for at least two of the nodes to see if there is a substantial match. In some implementations the decision is further based on information representative of a direction of arrival of respective received signals.