Method for asynchronously allocating a bandwidth, and an electronic communication device implementing this method

Abstract

Radio resources are dynamically allocated in a shared band communication system operating in direct mode (DMO). The communication system includes terminals organized in groups. Each group is allocated a resource from a number of resources available within the communication system. This process includes allocating to the group at least one other further resource from the number of resources until an attempted access to the further resource from the group to which the further resource had been allocated has been detected.

Claims

1. A method for allocating radio resources in a shared band communication system operating in direct mode, wherein the communication system includes a plurality of terminals organized in groups of terminals and communicating using a frame comprising: a first contention word and a second contention word, wherein the method comprises: statically allocating to each group of terminals a distinct resource from a plurality of resources within said communication system, wherein a first resource statically allocated to a first group of terminals is not simultaneously statically allocated to a second group of terminals, and wherein a second resource statically allocated to the second group of terminals is not simultaneously statically allocated to the first group of terminals, dynamically allocating to the first group of terminals, in addition to the first resource statically allocated to the first group of terminals, the second resource from said plurality of resources that is statically allocated to the second group of terminals; transmitting, by a terminal within the first group to other terminals within said first group, said frame over the first resource statically allocated to the first group and said frame over the second resource statically allocated to the second group and dynamically allocated to the first group, wherein said frame transmitted over the first resource includes information in the first contention word to inform the other terminals of said first group that said terminal within the first group has priority over the first resource statically allocated to the first group, and with respect to terminals within the second group that may receive the transmission of the frame over the second resource by said terminal within the first group and be disturbed thereby, transmitting over the second resource statically allocated to the second group and dynamically allocated to the first group, by a terminal within the second group, to said terminal within the first group said frame with information in the second contention word to inform said terminal within the first group that said terminal within the second group is disturbed by the dynamic allocation and use of said second resource by said terminal within the first group.

2. The method according to claim 1, further comprising, in response to receiving said frame with information in the second contention word by said terminal in the first group, releasing the dynamic allocation of said second resource.

3. The method according to claim 1, further comprising detecting an attempted access to said second resource by said terminal in the first group by said terminal in the second group by receipt of said frame with information in the first contention word.

4. The method according to claim 1, further comprising obtaining the plurality of resources by separating the shared band according to a frequency access.

5. The method according to claim 1, further comprising obtaining the plurality of resources by separating the shared band according to a time access.

6. The method according to claim 1, further comprising obtaining the plurality of resources by separating the shared band according to a time and frequency access.

7. A method, comprising: statically allocating to a first group of terminals a first communications resource; statically allocating to a second group of terminals a second communications resource; wherein the first communications resource statically allocated to the first group of terminals is not simultaneously statically allocated to the second group of terminals and wherein the second communication resource statically allocated to the second group of terminals is not simultaneously statically allocated to the first group of terminals; dynamically allocating to the first group of terminals, in addition to the first communications resource statically allocated to the first group of terminals, the second communications resource that is statically allocated to the second group of terminals; making a communication by a terminal within the first group to the plurality of terminals in the first group over both the first communications resource and the second communications resource, wherein said communication by the terminal within the first group of the first communications resource uses a first frame including information informing other terminals of said first group that said terminal within the first group has priority over the first communications resource statically allocated to the first group; with respect to terminals of said second group that may receive said communication by said terminal within the first group over said second communications resource and be disturbed thereby, making a communication by a terminal within the second group over said second communications resource using a second frame including information informing said terminal within the first group that said terminal within the second group is disturbed by said communication made by said terminal within the first group; and in response to receipt of said communication by said terminal within the first group, terminating the dynamic allocation to the first group of terminals of the second communications resource that is statically allocated to the second group of terminals.

8. The method of claim 7, wherein said first and second frames each include a first contention word and a second contention word, wherein said information informing said other terminals of said first group that said terminal within the first group has priority over the first communications resource statically allocated to the first group is transmitted in the first contention word, and wherein said information informing said terminal within the first group that said at least one terminal within the second group is disturbed by said communication made by said terminal within the first group is transmitted in the second contention word.

Description

DESCRIPTIONS OF THE FIGURES

(1) Other advantages and features of the invention will appear upon reading the detailed description of implementations and embodiments in no way limiting, of exemplary values and the following appended drawings:

(2) FIG. 1 is a view of a bandwidth allocation method according to prior art, and

(3) FIG. 2 is a representation of a frame used for implementing a method according to the invention, and

(4) FIG. 3 is a representation of frames used for implementing a method according to the invention,

(5) FIG. 4 is a view of a modified LTE protocol according to the invention,

(6) FIG. 5 is a view of a modification of LTE protocol according to the invention,

(7) FIG. 6 is a view of an embodiment of the method according to the invention,

(8) FIG. 7 is a view of another embodiment of the method according to the invention,

(9) FIG. 8 is a view of another embodiment of a method according to the invention,

(10) FIG. 9 is a view of another embodiment of a method according to the invention, and

(11) FIG. 10 is a view of an embodiment of a device according to the invention.

(12) In reference to FIG. 1, a first group G0 of terminals T01, T02, T03, T04, and a second group G1 of terminals T11, T12, T13 are respectively connected to resources R0, R1 from a plurality of resources R0-R3. All these terminals use a DMO type protocol.

(13) Resources R2 and R3 are not assigned to any group of terminals.

(14) When a terminal desires to transmit data, for example T01, it first listens to all the resources (R0, R1, R2, R3, R4). If one or more resources are unoccupied, this terminal emits data on the at least one of these unoccupied resources according to a frame illustrated in FIG. 2.

(15) The frame comprises: a synchronization word S; a format word F; six data words D; a first contention word Cont1; a second contention word Cont2.

(16) The word S is used by the members of a group to be synchronized. The word F announces the format of the frame. The six data words D comprise the payload.

(17) The first contention word Cont1, also called first contention slot, enables the priority to be used within a group. Thus, a member of the group can specify that it has priority using Cont1 slot. When a member of the same group receives such a frame, the same knows that it must release the occupied radio resource or not occupy it.

(18) The second contention word Cont2, also called second contention slot, enables a terminal disturbed by a use of a resource its group of which is owner to inform it to the disturbing terminal(s), also called guest terminal(s). This second word can be used on a specific resource only by a terminal belonging to a group being owner of this specific resource, also called local group.

(19) Since resources R1, R2, R3 are free, terminal T01 transmits data on all these resources. Terminal T01 transmits data on three further resources.

(20) Thus, terminal T01 increases in transmission capacity by occupying resources which are not dedicated thereto, that is resources for which group G0 is not an owner.

(21) When a member of the group—in this description, terminal T11—to which belongs an occupied resource is disturbed by the data transmission by T01, terminal T11 transmits a frame on resource R1 and informs it is disturbed by using the Cont2 slot. Upon receiving this frame, terminal T01 stops using resource R1. Resource R1 is then released by terminal T01. Thus, the detection of an attempted access to further resource R1 by a terminal of group G1 to which further resource R1 has been allocated comprises a step of notifying by terminal T11 of group G1 to which further resource R1 had been allocated.

(22) As illustrated in FIG. 3, frames are synchronized using previously described synchronization word S. A terminal must listen to all the resources it occupies and which are not assigned thereto before continuing to transmit on resources which do not belong thereto.

(23) The principle of a modification of LTE protocol using a method according to the invention will now be illustrated in reference to FIGS. 4 and 5.

(24) Both time T and frequency F axes appear in these figures. Several missions are also shown in these figures.

(25) Missions 1, 2, 3, 4, 5 and 6 are represented in FIG. 4.

(26) The paving of the radio resource is based on principles of TETRA protocol. The paving is thus performed in frequency according to a splitting of a bandwidth of 1.4 MHz into six RB (“Resource Block”) each having a band of 180 KHz (180 KHz*6=1.4 MHz). Thus, each mission is assigned a communication channel and the possible rate per mission is 100 Kbits/s using a suitable modulation and coding scheme. The method according to the invention herein enables six co-located missions to be deployed.

(27) In this modification of LTE protocol, a new initial synchronization frame according to the invention is used.

(28) In reference to FIG. 5, it is shown that each of the previously described RB can be subdivided into three sub-RB. The point is to be able to support the 18 groups represented in FIG. 5 by assigning a sub-RB to each group.

(29) The rate of each of the groups is thus substantially equal to 33 Kbits/s.

(30) The new synchronization frame according to the invention is also used. Moreover, the format word F according to the invention is in this case used to describe the modified LTE frame.

(31) In reference to FIG. 6, the use of a method according to the invention is used when a plurality of resources is obtained by separating the shared band according to a time access.

(32) Thus, a same frequency band can be subdivided as illustrated in FIG. 6 by using a division by four of the period of time assigned to each group. By being locating in a rate of 100 Kbps and by separating this time shared resource into four groups represented in the figure, each of these groups then has a rate of 25 Kbps once a time synchronization has been implemented. A rate of 25 Kbps is sufficient to transmit voice type data on a channel.

(33) With the method according to the invention, a terminal belonging to the first group can use the second time resource of the second group. By overlapping this resource, the terminal of this first group can multiply its rate by two.

(34) This is shown in FIG. 7, in which it can be seen that since the third group is not present, the first group uses the resources which were allocated to the third group. Thus, the first group has its rate multiplied by two. It is also observed that the time overlapping is not continuous in time since the resources of the second group are not used by the first group.

(35) In reference to FIG. 8, it is illustrated a space and frequency paving of the use of the radio resource.

(36) The radio resource is divided into three frequency bands.

(37) A first frequency band occupies two channels of 42 Kbps. This frequency band is also divided in time into two groups, the groups 1 and 2 which alternately occupy it over time.

(38) A second frequency band occupies four channels of 24 Kbps. This frequency band is also divided in time into four groups, groups 10, 11, 12 and 13 which alternately occupy it over time.

(39) A third frequency band occupies two channels of 42 Kbps. This frequency band is also divided in time into two groups, groups 20 and 21 which alternately occupy it over time.

(40) With the method according to the invention, group 1 will detect the absence of group 2 and group 10 will be able to detect the absence of groups 11, 12, 13 and 21.

(41) A possible result of the use of available resources with the use of an embodiment of the method according to the invention is illustrated in FIG. 9.

(42) Thus, FIG. 9 shows that the first frequency band described in FIG. 8 will be occupied in time according to a sequence Group1, Group1, Group1, void, Group1, Group1, Group1, void, Group1, void.

(43) Thus, it can be seen that the occupation of the time resources is itself likely to change in time.

(44) The second frequency band described in FIG. 8 is wholly occupied by group 10 which has noticed the absence of groups 11, 12 and 13.

(45) Finally, the third frequency band described in FIG. 8 is herein used alternately with groups 10 and 20, group using the frequency band released by the absence of group 21.

(46) According to another embodiment not represented, the method according to the invention can be used to set up a two hop communication between terminals of a same group. The resource assigned to the first terminal is thus dynamically separated for the purpose to be able to be used for direct one hop communication on the one hand, and contain in a separated resource the content of the two hop communication on the other hand.

(47) FIG. 10 illustrates an embodiment of devices according to the invention.

(48) A shared band communication system operating in direct mode is represented. This system comprises four terminals T01, T02, T03 and T04 belonging to a group of terminals G0 as well as three terminals T11, T12 and T13 belonging to a group of terminals G1. The terminals comprise an antenna providing wireless communication.

(49) A first resource R0 is allocated to group G0 of terminals. A second resource R1 is allocated to group G1 of terminals as is represented in the figure by solid lines. Thus, only two resources are allocated from the four resources available.

(50) Terminals T01, T02, T03, T04, T11, T12 and T13 comprise devices D01, D02, D03, D04, D11, D12 and D13 according to the invention, respectively. These devices are electronic communication modules as an electronic board insertable in the terminals and comprise data processing means.

(51) The processing means of these devices D01, D02, D03, D04, D11, D12 and D13 cooperate with the wireless communication means of terminals T01, T02, T03, T04, T11, T12 and T13 to allocate to the terminals at least one other further resource from the four resources. These allocations are performed according to a method according to the invention. The dotted lines in FIG. 10 illustrate the possibility for allocating these resources to the terminals by the devices. These allocations remain operating until an attempted access to a further resource from the group to which the further resource had been allocated has been detected.

(52) According to another embodiment not represented, a device according to the invention is a module directly integrated to a terminal.

(53) Of course, the invention is not restricted to the examples just described and numerous alterations can be provided to these examples without departing from the scope of the invention.