Channel Allocation for Burst Transmission to a Diversity of Satellites

Abstract

A method for allocating transmission channels to devices configured to communicate short data packets to a diversity of non geostationary satellites is disclosed hereby. The method suggests a dynamic cellular partitioning of the earth surface, based on the smallest intersections of overlapping satellite service areas (“footprints”), defined as mega-cells, and reusing channels in different mega-cells. In addition, a transmission cycle is defined and divided to time slots, synchronized at each device by GPS timing signals, and mega-cells served by more satellites are allocated with fewer time slots, in order to increase the chance of transmitters placed in mega-cells served by fewer satellites to be detected. Further, each mega-cell is divided to cells, and different channels and time slots are allocated to each cell, from those allocated to the corresponding mega-cell. Consequently, collision of transmissions from different mega-cells is reduced, and collision of transmissions from different cells in a mega-cell is avoided.

Description

BACKGROUND OF INVENTION[0001]When two communication devices simultaneously transmit on the same channel, a communication conflict might occur, potentially degrading the receiving probability of one or both of these transmissions. Such communication conflicts are obviously undesired, yet cannot be disregarded in the crowded communication networks which are usually short in bandwidth.[0002]The penalty for such transmission collisions is a lower quality of service, more power consumption and more undesired RF radiation. Therefore, multiple access communication networks employ methods to properly allocate communication channels to devices, in order to avoid such conflicts. Still, due to the high ratio of devices per channel, and to the often unsynchronized transmissions, among different devices and users that share these channels, such conflicts are still an important issue to consider in communication systems.[0003]One communication sector particularly vulnerable to channel allocation ...

AI Technical Summary

Benefits of technology

"The invention is a method for allocating transmission channels to multiple devices in a communication network. The method takes into account the current time and location of the devices, as well as the footprints of the satellites. The method allows for the allocation of channels to mega-cells, which are intersections of footprints. By dividing each mega-cell into cells and allocating different channels and time slots to each cell, the method ensures that devices in different mega-cells do not interfere with each other. This improves the transmission probability of the underprivileged devices and ensures that the network resources are shared more evenly among the devices. The method can be further refined by taking into account parameters such as the geographical distribution of devices and the statistics of device density."

Problems solved by technology

When two communication devices simultaneously transmit on the same channel, a communication conflict might occur, potentially degrading the receiving probability of one or both of these transmissions.

Such communication conflicts are obviously undesired, yet cannot be disregarded in the crowded communication networks which are usually short in bandwidth.

The penalty for such transmission collisions is a lower quality of service, more power consumption and more undesired RF radiation.

Still, due to the high ratio of devices per channel, and to the often unsynchronized transmissions, among different devices and users that share these channels, such conflicts are still an important issue to consider in communication systems.

One communication sector particularly vulnerable to channel allocation conflicts is related to networks comprising a multitude of one-way transmitters that share a relatively small amount of channels.

In such networks, transmitters cannot coordinate with each other the allocation of channels, so there is a chance that two such devices will simultaneously transmit on the same channel and interfere with each other.

However, as tens and hundreds of thousands of such beacons are deployed, sharing one narrowband channel, simultaneous transmissions might statistically occur, interfering with each other and decreasing the probability of a distress message to be detected.

Another aspect of communications vulnerable to channel allocation conflicts is the initial approach of a device to an access point asking for service.

At this preliminary phase, these devices might not be synchronized with each other, for different reasons, such as: random timing of access, no peer to peer connection; communication peaks; etc.

Yet, none of these three U.S. patents addresses intersections of footprints, i.e. areas served by several satellites, and neither Berstis nor Amouris suggests discriminating between devices placed in areas served by a different number of satellites, for channel allocation purposes.

Yet, Jan does not address cells contained in other than one or two footprints, and neither suggests allocating active transmission channels to devices in overlapping footprints, specifically not according to the number of overlapping footprints.

Still, this method does not address intersections of footprints for the purpose of resource allocation.

The present art methods described above have not yet provided satisfactory solutions to the problem of allocating communication channels to devices configured to transmit bursts of data to a diversity of satellites, specifically non geostationary satellites, sharing relatively few channels, particularly when having a certain amount of data transmission redundancy.

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