Protocol and mechanism for centralized asset tracking communications
First Claim
Patent Images
1. A method of communicating between a central station and a plurality of tracking units affixed to mobile assets, comprising the steps of:
- polling, from the central station, each of said plurality of tracking units on a narrow band forward channel;
each of said tracking units responding to said narrow band forward channel only at a predetermined time;
each of said tracking units further monitoring a flag in said narrow band forward channel to estimate when to next receive said narrow band forward channel;
each of said plurality of tracking units responding to said polling on a narrow band return channel, each of said plurality of tracking units respectively including in its response data and an indication as to whether the respective tracking unit has additional data to transmit to the central station;
receiving responses and data from each of the plurality of tracking units at said central station;
compiling, at said central station, a list of tracking units which have additional data to transmit to said central station.assigning a scheduled transmit time for each tracking unit having additional data to transmit;
transmitting, on said narrow band forward channel to each respective tracking unit having additional data to transmit, the scheduled transmit time to transmit said additional data; and
receiving data from said each respective tracking unit having additional data to transmit at the scheduled transmit times.
1 Assignment
0 Petitions
Accused Products
Abstract
A protocol and mechanism which provide for centralized asset tracking communications from a central station are based on a control/polling forward channel; i.e., a narrow band channel from the central station to tracking units affixed to the assets. A narrow band service channel is used by the asset tracking units to transmit to the central station to aid the central station in efficient scheduling of asset reporting, and a plurality of narrow band channels that are appropriately multiplexed are used for conveyance of data from the asset tracking units to the central station.
81 Citations
10 Claims
-
1. A method of communicating between a central station and a plurality of tracking units affixed to mobile assets, comprising the steps of:
-
polling, from the central station, each of said plurality of tracking units on a narrow band forward channel; each of said tracking units responding to said narrow band forward channel only at a predetermined time; each of said tracking units further monitoring a flag in said narrow band forward channel to estimate when to next receive said narrow band forward channel; each of said plurality of tracking units responding to said polling on a narrow band return channel, each of said plurality of tracking units respectively including in its response data and an indication as to whether the respective tracking unit has additional data to transmit to the central station; receiving responses and data from each of the plurality of tracking units at said central station; compiling, at said central station, a list of tracking units which have additional data to transmit to said central station. assigning a scheduled transmit time for each tracking unit having additional data to transmit; transmitting, on said narrow band forward channel to each respective tracking unit having additional data to transmit, the scheduled transmit time to transmit said additional data; and receiving data from said each respective tracking unit having additional data to transmit at the scheduled transmit times. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An efficient method of communicating between a central station and a plurality of tracking units affixed to mobile assets, comprising the steps of:
-
forming at least one dynamic mobile local area network (LAN) as a subset of said plurality of tracking units, each of the tracking units in the LAN being a node of said LAN; assigning one tracking unit in said LAN to be a master tracking unit and assigning each of the remaining tracking units in said LAN to be respective slave tracking units; communicating between each of said slave tracking units and said respective LAN master tracking unit; communicating between each of said respective master tacking units and central station such that each respective one of said LAN master tracking units transmits data from each of said respective slave tracking units within said master tracking unit'"'"'s respective LAN to said central station. - View Dependent Claims (9, 10)
-
Specification