METHOD FOR DEFINING AND APPLYING A FREQUENCY PLAN

• US 20170366194A1
• Filed: 05/23/2017
• Published: 12/21/2017
• Est. Priority Date: 06/15/2016
• Status: Active Grant

• Current Assignee: Sagemcom Energy & Telecom SAS (Sagemcom Holding SAS)
• Original Assignee: Sagemcom Energy & Telecom SAS (Sagemcom Holding SAS)
• Inventors: SENNOUN, Yassir, HARNAY, Franck
• Granted Patent: US 10,277,234 B2
• Time in Patent Office: Days
• CPC Class Codes: H03D 7/163 the local oscillations of at least two of the frequency changers being derived from a single oscillator
• CPC Class Codes: H03L 7/1974 for fractional frequency division
• CPC Class Codes: H04B 1/403 using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In a communication system of the LPWAN type including a server and a plurality of gateways intended to make wireless communications with terminals in said communication system, the server: obtains a description of a mobility hierarchy in which mobility types are hierarchically defined; obtains a description of a mobility tree in which mobility areas are hierarchically defined, in conformity with the mobility hierarchy; obtains terrain measurements associated with each mobility area defined in the mobility tree; establishes a frequency plan on the basis of the mobility tree and terrain measurements; and configures the gateways and the terminals according to the frequency plan established.

Claims

1. A method for defining and applying a frequency plan in a communication system of the LPWAN type comprising a server and a plurality of gateways connected to said server, the plurality of gateways using frequency bands for making wireless communications with terminals in the communication system, wherein the server performs the following steps:

obtaining a description of a mobility hierarchy in which mobility types are hierarchically defined;

obtaining a description of a mobility tree in which the mobility areas are hierarchically defined, each mobility area having a mobility type in conformity with the mobility hierarchy;

obtaining terrain measurements associated with each mobility area defined in the mobility tree;

determining, from the terrain measurements, for each mobility area, information on the percentage of time during which the terrain measurements show a received signal level RSSI lower than such and such a received signal level RSSI threshold from a predefined set of received signal level RSSI thresholds;

in that the server runs through the mobility tree by iterating the following steps;

selecting the mobility area with the highest hierarchical degree not yet processed;

determining, for the mobility area selected, a mean probability P_m for each frequency band, from said time-percentage information determined for each mobility area that is a leaf of the tree and is hierarchically attached to the mobility area selected;

allocating, for the mobility area detected, up to a quantity P of frequency bands having the best mean probabilities;

in that the server performs the following steps for configuring the gateways vis-á

-vis the frequency plan;

obtaining descriptions of mobility ranges in which groupings of mobility areas are made and in which, for each grouping, a list of gateways is associated with each grouping in order to indicate which gateways are intended to support said grouping;

configuring each gateway according to said descriptions of ranges and frequency bands allocated to the mobility areas constituting said groupings;

in that, on reception from a terminal of a request for connection to the communication system, the server obtains a description of the terminal from a terminal identifier included in said request, the description including a list of mobility types to which said terminal has a right of access, and the server iterates the following steps for all the mobility types to which said terminal has a right of access;

identifying the mobility type with the highest hierarchical degree;

identifying which mobility areas correspond to said mobility type with the highest hierarchical degree identified;

selecting a mobility area from the mobility areas identified;

allocating said terminal at least one frequency band allocated to the mobility area selected;

and wherein the server configures said terminal according to the frequency bands thus allocated to said terminal.

2. The method according to claim 1, wherein the mean probability P_m is calculated as follows:

3. The method according to claim 1, wherein, to configure said terminal, the server performs the following steps:

informing a first lot of frequency bands allocated to the terminal, via a message responding to the request received; and

informing a second lot of frequency bands allocated to the terminal, via one or more supplementary messages.

4. The method according to claim 1, wherein channels form groupings of consecutive frequency bands, and the server allocates the frequency bands to a channel base.

5. The method according to claim 1, wherein the server obtains the description of the mobility hierarchy, the description of the mobility tree, the terrain measurements and the description of each terminal from another server external to the communication system.

6. The method according to claim 5, wherein the server checks that the mobility type of each mobility area of the mobility tree has a hierarchical degree lower than the mobility type of another mobility area to which said mobility area is directly attached in the mobility tree.

7. The method according to claim 1, wherein the description of each terminal comprises information indicating whether the terminal is supposed to be fixed, and the server performs the following steps vis-á

-vis the terminal that sent the request received;

determining the list of frequency bands eligible for said terminal;

determining the frequency bands in this list that were allocated to at least three gateways among the gateways that relayed said request; and

allocating the frequency bands thus determined to said EP terminal.

8. The method according to claim 7, wherein, for the frequencies not selected in said list of eligible frequency bands, the server waits until it receives other frames coming from said terminal in order to determine whether new gateways have relayed said other frames and thus determine whether other frequency bands in said list of the eligible frequency bands have been allocated to at least three gateways among the gateways that relayed said other frames.

9. The method according to claim 8, wherein, in the case where the quantity of gateways receiving uplink frames coming from said terminal remains strictly less than three, the server sends an alert.

10. A computer program product embodied in a non-transitory computer readable medium containing a set of instructions causing the execution, by a processor of a server intended to be included in a long-range extended network of the LPWAN type, of the method according to claim 1, when said computer program is executed by said processor.

11. A non-transitory information storage medium storing a computer program containing a set of instructions causing the execution, by a processor of a server intended to be included in a long-range extended network of the LPWAN type, of the method according to claim 1, when said computer program is executed by said processor.

12. A server configured so as to define and apply a frequency plan in a communication system of the LPWAN type comprising, apart from said server, a plurality of gateways connected to said server, the plurality of gateways using frequency bands for effecting wireless communications with terminals in the communication system, wherein the server is configured to:

obtain a description of a mobility hierarchy in which mobility types are hierarchically defined;

obtain a description of a mobility tree in which mobility areas are hierarchically defined, each mobility area having a mobility type in conformity with the mobility hierarchy;

obtain terrain measurements associated with each mobility area defined in the mobility tree;

determine, from the terrain measurements, for each mobility area, information on the percentage of time during which the terrain measurements show a received signal level RSSI lower than such and such a received signal level RSSI threshold from a predefined set of received signal level RSSI thresholds;

wherein the server is configured so as to run though the mobility tree by iterating the following steps;

selecting the mobility area with the highest hierarchical degree not yet processed;

determining, for the mobility area selected, a mean probability P_m for each frequency band, from said time-percentage information determined for each mobility area that is a leaf of the tree and is hierarchically attached to the mobility area selected;

allocating, or the mobility area selected, up to a quantity P of frequency bands having the best mean probabilities;

wherein the server is configured so as to perform the following steps for configuring the gateways vis-á

-vis the frequency plan;

obtaining descriptions of mobility ranges in which groupings of mobility areas are made and in which, for each grouping, a list of gateways is associated with each grouping in order to indicate which gateways are intended to support said grouping;

configuring each gateway according to said descriptions of ranges and frequency bands allocated to the mobility areas constituting said groupings;

wherein, on reception from a terminal of a request for connection to the communication system, the server is configured to obtain a description of the terminal from a terminal identifier included in said request, the description including a list of mobility types to which said terminal has a right of access, and to iterate the following steps for all the mobility types to which said terminal has a right of access;

identifying the mobility type with the highest hierarchical degree;

identifying which mobility areas correspond to said mobility type with the highest hierarchical degree identified;

selecting a mobility area from the mobility areas identified;

allocating to said terminal at least one frequency band allocated to the mobility area selected;

and wherein the server is configured to configure said terminal according to the frequency bands thus allocated to said terminal.