Summary of the technology
A procedure for positioning wireless nodes under a passive approach, i.e., just listening to the radio medium has been developed. Thus, each regular location process run to locate a specific wireless node in the network yields to several nodes knowing their own position. Partners to further develop the system and/ or to establish commercial agreements with technical cooperation are sought.
Positioning wireless nodes using time-of-flight measurements is constrained by several factors. One of the most important is the load in the wireless access network: the more traffic in the access network the more delay (i.e. error) in the measurements. Thus, location system has to control the access of the nodes and the provision of services requesting the position of all (of a noticeable number of) nodes in the network to guarantee the location quality of service. Accordingly, scalability becomes a key factor in the deployment of time-based location systems and must be addressed properly.
This patented technology allows nodes to be passively positioned in a collaborative network where few wireless nodes (called active nodes) run a 2-way TOA location technique. Active nodes compute the distance to several landmarks measuring the time-offlight to them. This is done using round-trip-time procedure: sending a packet from the active node to the landmark, which sends back and answer to the active node. During this procedure, passive nodes listen to the radio and, taking specific timestamps are able to compute time-differences related with the position of the landmarks and the active node.
Once enough measurements are taken, passive nodes are able to compute first the position of the active node and then their own position, all this without injecting more traffic in the network and improving thus the scalability of the location system.
Current stage of development
The procedure and system have been completely defined and formulated. The system has been extensively simulated and confirms the performance expectances. Implementation in a IEEE 802.11 network is planned.
Applications and Target Market
This technology can be applied in any current or future location system addressed to medium to large networks or constrained environments (e.g. location systems deployed indoors).
· Joint positioning of active and passive nodes
· Improving the scalability: wireless nodes can be positioned under a passive approach (no traffic is generated for location purposes)
· Improving the integrity: passive positioning can be run in dark areas (i.e. where active positioning is not possible)
· Intensive location traffic services can be provided (e.g. the position of all the nodes in the network)
· Smarter network operation and management tasks can be provided
Intellectual property status
Technology available for licensing with technical cooperation Patent Status Two patents applied
Universitat Politècnica de Catalunya - UPC
Technology Transfer Office