U.S. patent application number 17/043791 was filed with the patent office on 2021-01-28 for terminal, radio communication system, and communication method.
This patent application is currently assigned to NEC CORPORATION. The applicant listed for this patent is NEC CORPORATION. Invention is credited to Leonardo LANANTE, Yuhei NAGAO, Hiroshi OCHI, Tatsumi UWAI.
Application Number | 20210029665 17/043791 |
Document ID | / |
Family ID | 1000005166046 |
Filed Date | 2021-01-28 |
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United States Patent
Application |
20210029665 |
Kind Code |
A1 |
LANANTE; Leonardo ; et
al. |
January 28, 2021 |
TERMINAL, RADIO COMMUNICATION SYSTEM, AND COMMUNICATION METHOD
Abstract
A terminal (10) includes an Initiator functional unit (13) for
acquiring information to be used for estimating position
information of the terminal by performing frame exchange with a
neighboring Responder terminal, a Responder functional unit (14)
for providing the information to be used for estimating the
position information of the Initiator terminal by performing the
frame exchange with a neighboring Initiator terminal, and a control
unit (12) for controlling the Initiator functional unit (13) and
the Responder functional unit (14). The control unit (12) estimates
the position information of the terminal (10) based on the
information acquired by controlling the terminal (10) to function
as the Initiator terminal using the Initiator functional unit (13)
and by controlling the terminal (10) to exchange frames with the
neighboring Responder terminal, and then controls the terminal (10)
to function as the Responder terminal using the Responder
functional unit (14) and the position information.
Inventors: |
LANANTE; Leonardo;
(Kitakyushu-shi, Fukuoka, JP) ; NAGAO; Yuhei;
(Iizuka-shi, Fukuoka, JP) ; OCHI; Hiroshi;
(Kitakyushu-shi, Fukuoka, JP) ; UWAI; Tatsumi;
(Iizuka-shi, Fukuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NEC CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
NEC CORPORATION
Tokyo
JP
|
Family ID: |
1000005166046 |
Appl. No.: |
17/043791 |
Filed: |
March 8, 2019 |
PCT Filed: |
March 8, 2019 |
PCT NO: |
PCT/JP2019/009513 |
371 Date: |
September 30, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B 7/086 20130101;
H04W 64/003 20130101; H04W 72/0446 20130101; H04W 8/005
20130101 |
International
Class: |
H04W 64/00 20060101
H04W064/00; H04B 7/08 20060101 H04B007/08; H04W 72/04 20060101
H04W072/04; H04W 8/00 20060101 H04W008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2018 |
JP |
2018-080308 |
Claims
1. A terminal comprising: a memory configured to store
instructions; and at least one processor configured to process the
instructions to: acquire information for estimating position
information of the terminal via frame exchange with a neighboring
Responder terminal, to function as an Initiator terminal, estimate
the position information of the terminal based on the information
for estimating the position information of the terminal, and
provide the information for estimating the position information of
a neighboring Initiator terminal via frame exchange with the
neighboring Initiator terminal to function as a Responder terminal
in a case where the position information of the terminal has been
estimated.
2. The terminal according to claim 1, wherein in a case where the
terminal functions as the Responder terminal, the at least one
processor is configured to process the instructions to signal a
Responder information element indicating that the terminal is the
Responder terminal to a neighboring terminal, and in a case where
the terminal functions as the Initiator terminal, the at least one
processor is configured to process the instructions to: discover
the neighboring Responder terminal signaling the Responder
information element, negotiate frame exchange with the discovered
neighboring Responder terminal, and acquire the information to be
used for estimating the position information of the terminal via
the frame exchange with the discovered neighboring Responder
terminal in response to negotiation of the frame exchange.
3. The terminal according to claim 1, wherein the information for
estimating the position information of the terminal includes the
position information of the neighboring Responder terminal and ToA
(Time of Arrival) information indicating a time when the frame
exchange is performed with the neighboring Responder terminal.
4. The terminal according to claim 3, wherein performing the frame
exchange includes performing an FTM (Fine Time Measurement)
protocol.
5. The terminal according to claim 1, wherein the information for
estimating the position information of the terminal includes the
position information of the neighboring Responder terminal and AoA
(Angle of Arrival) information indicating an angle of the
neighboring Responder terminal when the frame exchange is performed
with the neighboring Responder terminal.
6. A radio communication system comprising: a plurality of
terminals, wherein each terminal of the plurality of the terminals
is configured to function as either an Initiator terminal
configured to acquire information for estimating position
information of the each terminal via frame exchange with a
neighboring Responder terminal or a Responder terminal configured
to provide the information for estimating the position information
of a neighboring Initiator terminal via the frame exchange with the
neighboring Initiator terminal, wherein the each terminal of the
plurality of terminals is configured to estimate the position
information of the each terminal based on the information for
estimating position information of the each terminal and function
as the Responder terminal in a case where the position information
of the each terminal has been estimated.
7. The radio communication system according to claim 6, wherein in
a case where the each terminal of the plurality of the terminals
functions as the Responder terminal, the each terminal is
configured to signal a Responder information element indicating
that the terminal is the Responder terminal to a neighboring
terminal, and in a case where the each terminal of the plurality of
the terminals functions as the Initiator terminal, the each
terminal is configured to: discover the neighboring Responder
terminal signaling the Responder information element, negotiate
frame exchange with the discovered neighboring Responder terminal,
and acquire the information for estimating the position information
of the each terminal via the frame exchange with the discovered
neighboring Responder terminal in response to negotiation of the
frame exchange.
8. The radio communication system according to claim 6, wherein the
information for estimating the position information of the each
terminal of the plurality of the terminals includes the position
information of the neighboring Responder terminal and ToA (Time of
Arrival) information indicating a time when the frame exchange is
performed with the neighboring Responder terminal.
9. The radio communication system according to claim 8, wherein
performing the frame exchange includes performing an FTM (Fine Time
Measurement) protocol.
10. The radio communication system according to claim 6, wherein
the information for estimating the position information of the each
terminal of the plurality of the terminals includes the position
information of the neighboring Responder terminal and AoA (Angle of
Arrival) information indicating an angle of the neighboring
Responder terminal when the frame exchange is performed with the
neighboring Responder terminal.
11. A communication method performed by a terminal comprising:
acquiring information for estimating position information of the
terminal via frame exchange with a neighboring Responder terminal,
to function as an Initiator terminal; estimating the position
information of the terminal based on the information for estimating
the position information of the terminal; and providing the
information for estimating the position information of a
neighboring Initiator terminal via frame exchange with the
neighboring Initiator terminal to function as a Responder terminal
in a case where the position information of the terminal has been
estimated.
12. The communication method according to claim 11, further
comprising: in a case where the terminal functions as the Responder
terminal, signaling a Responder information element indicating that
the terminal is the Responder terminal to a neighboring terminal,
and in a case where the terminal functions as the Initiator
terminal, discovering the neighboring Responder terminal signaling
the Responder information element, negotiating frame exchange with
the discovered neighboring Responder terminal, and acquiring the
information for estimating the position information of the terminal
via the frame exchange with the discovered neighboring Responder
terminal in response to negotiation of the frame exchange.
13. The communication method according to claim 11, wherein the
information for estimating the position information of the terminal
includes the position information of the neighboring Responder
terminal and ToA (Time of Arrival) information indicating a time
when the frame exchange is performed with the neighboring Responder
terminal.
14. The communication method according to claim 13, wherein
performing the frame exchange includes performing an FTM (Fine Time
Measurement) protocol.
15. The communication method according to claim 11, wherein the
information for estimating the position information of the terminal
includes the position information of the neighboring Responder
terminal and AoA (Angle of Arrival) information indicating an angle
of the neighboring Responder terminal when the frame exchange is
performed with the neighboring Responder terminal.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a terminal, a radio
communication system, and a communication method.
BACKGROUND ART
[0002] In the wireless LAN (Local Area Network) standard IEEE
(Institute of Electrical and Electronics Engineers) 802.11, the
Next Generation Positioning (NGP) 802.11az is studied by the task
group TGaz (e.g., Non Patent Literature 1 and 2). 802.11az (NGP) is
expected to be introduced into the next generation radio
communication system using a wireless LAN in order to achieve
high-precision positioning by wireless LAN without relying on GPS
(Global Positioning System) satellites, etc.
[0003] In 802.11az (NGP), the FTM (Fine Time Measurement) protocol
is performed between an Initiator terminal and a Responder
terminal, so that the Initiator terminal can acquire information
used for estimating the position information of the Initiator
terminal and estimate the position information of the Initiator
terminal based on this information. Here, the Initiator terminal
exchanges frames (exchange of one frame or exchange of a plurality
of frames. The same shall apply hereinafter) with neighboring
Responder terminals in order to acquire information used to
estimate the position information of the Initiator terminal. The
Responder terminal exchanges frames with a neighboring Initiator
terminal to thereby provide information used to estimate the
position information of the Initiator terminal.
[0004] FTM is technology based on ToA (Time of Arrival)
information. When the FTM protocol is performed, frames are
exchanged between the Initiator terminal and the Responder
terminal, so that the Initiator terminal can acquire, as the
information used to estimate the position information of the
Initiator terminal, the position information of the Responder
terminal and time information (ToA Information) indicating the time
when the frame exchange is performed with the Responder
terminal.
[0005] A basic configuration of a radio communication system using
a wireless LAN and an operation behavior of the FTM protocol will
be described below.
[0006] The basic configuration of the radio communication system
using the wireless LAN will be described with reference to FIG.
1.
[0007] As shown in FIG. 1, the radio communication system includes
an Initiator terminal 10I (in FIG. 1, one Initiator terminal 10I1)
and Responder terminals 10R (in FIG. 1, four Responder terminals
10R1 to 10R4). The number of Initiator terminals 10I and the number
of Responder terminals 10R are not limited to those shown in FIG.
1. Hereinafter, when the Initiator terminal 10I and the Responder
terminal 10R are not specified, they are simply referred to as a
"terminal 10".
[0008] An operation behavior of the FTM protocol between the
Initiator terminal 10I and the Responder terminal 10R will be
described with reference to FIGS. 2 and 3. FIG. 2 is a timing
diagram, and FIG. 3 is a sequence diagram.
[0009] As shown in FIGS. 2 and 3, firstly, the Initiator terminal
10I transmits, to the Responder terminal 10R, an NDPA (Null Data
Packet) frame 901 announcing a transmission of an NDP (NDP
Announce) frame, and then transmits the NDP frame 902.
[0010] In response to this, the Responder terminal 10R transmits an
NDP frame 903 to the Initiator terminal 10I, and then transmits an
LMR (Location Measurement Report) Feedback frame 904. The LMR
feedback frame 904 includes time information about the time t2 when
the NDP frame 902 is received from the Initiator terminal 10I and
about the time t3 when the NDP frame 903 is transmitted to the
Initiator terminal 10I, and the position information of the
Responder terminal 10R.
[0011] The Initiator terminal 10I can acquire the time information
about the times t2 and t3 by the LMR Feedback frame 904 received
from the Responder terminal 10R. The Initiator terminal 10I can
also acquire by itself the time information about the time t1 when
the NDP frame 902 is transmitted to the Responder terminal 10R and
about the time t4 when the NDP frame 903 is received from the
Responder terminal 10R. Therefore, the Initiator terminal 10I can
estimate an inter-terminal distance between the Initiator terminal
10I and the Responder terminal 10R based on the time information
about the times t1, t2, t3, and t4. The Initiator terminal 10I can
also acquire the position information of the Responder terminal 10R
by the LMR Feedback frame 904.
[0012] Further, the Initiator terminal 10I performs the FTM
protocol with a plurality of Responder terminals 10R, and acquires
the position information of each Responder terminal 10R and the
inter-terminal distance between the Initiator terminal 10I and each
Responder terminal 10R, so that the position information of the
Initiator terminal 10I can be estimated.
CITATION LIST
Non Patent Literature
[0013] Non Patent Literature 1: Chao-Chun Wang (MediaTek Inc), IEEE
802.11-17/0462r12, "Specification Framework for TGaz", 2018 Jan.
16, [searched on Mar. 7, 2018], the Internet
<https://mentorieee.org/802.11/dcn/17/11-17-0462-12-00az-11-az-tg-sfd.-
doc>
[0014] Non Patent Literature 2: Ganesh Venkatesan (Intel
Corporation), IEEE 802.11-18/0215r2, "802.11[802.11az Negotiation
Protocol] (relative to REVmd D0.4)", Jan. 10, 2018, [searched on
Mar. 7, 2018], the Internet
<https://mentorieee.org/802.11/dcn/18/11-18-0215-02-00az-802-11az-nego-
tiation-protocol-amendment-text.doc>
SUMMARY OF INVENTION
Technical Problem
[0015] In the radio communication system according to the related
art, if a sufficient number of Responder terminals 10R are not
present, the positioning coverage, which is a range in which
positioning is available by the Initiator terminal 10I, becomes
narrower. However, in order to prepare a sufficient number of
Responder terminals 10R to expand the positioning coverage, it is
necessary for the user to manually configure the terminals 10 to
function as the Responder terminals 10R, thereby increasing the
burden on the user.
[0016] Accordingly, one of objects of the present disclosure is to
solve the above-described problem and provide a terminal, a radio
communication system, and a communication method capable of
preparing a sufficient number of Responder terminals without
increasing a burden on a user.
Solution to Problem
[0017] An example aspect is a terminal including:
[0018] Initiator means for acquiring information to be used for
estimating position information of the terminal by performing frame
exchange with a neighboring Responder terminal;
[0019] Responder means for providing the information to be used for
estimating the position information of a neighboring Initiator
terminal by performing the frame exchange with the neighboring
Initiator terminal;
[0020] control means for controlling the Initiator means and the
Responder means.
[0021] The control means is configured to control the terminal to
function as the Initiator terminal using the Initiator means,
estimate the position information of the terminal based on the
information acquired by controlling the terminal to exchange frames
with the neighboring Responder terminal, and then control the
terminal to function as the Responder terminal using the Responder
means and the position information.
[0022] Another example aspect is a radio communication system
including:
[0023] a plurality of terminals, wherein
[0024] each terminal of the plurality of the terminals is
configured to function as either an Initiator terminal configured
to acquire information to be used for estimating position
information of the each terminal by performing frame exchange with
a neighboring Responder terminal or a Responder terminal configured
to provide the information to be used for estimating the position
information of a neighboring Initiator terminal by performing the
frame exchange with the neighboring Initiator terminal.
[0025] The each terminal is configured to function as the Initiator
terminal and estimate the position information of the each terminal
based on the information acquired by performing the frame exchange
with the neighboring Responder terminal and then function as the
Responder terminal using the position information.
[0026] Another example aspect is a communication method performed
by a terminal including:
[0027] controlling the terminal to function as an Initiator
terminal by estimating position information of the terminal based
on information acquired by performing frame exchange with a
neighboring Responder terminal and then controlling the terminal to
function as a Responder terminal by performing the frame exchange
with a neighboring Initiator terminal to thereby provide
information to be used for estimating the position information of
the neighboring Initiator terminal.
Advantageous Effects of Invention
[0028] According to the above-described aspect, it is possible to
provide a terminal, a radio communication system, and a
communication method capable of preparing a sufficient number of
Responder terminals without increasing a burden on a user.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 shows a configuration example of a radio
communication system;
[0030] FIG. 2 is a timing chart showing an operation example when
an FTM protocol is performed between an Initiator terminal and a
Responder terminal;
[0031] FIG. 3 is a sequence diagram showing an operation example
when the FTM protocol is performed between the Initiator terminal
and the Responder terminal;
[0032] FIG. 4 is a block diagram showing a configuration example of
a terminal according to an example embodiment;
[0033] FIG. 5 shows an operation example of a terminal according to
the example embodiment;
[0034] FIG. 6 shows an operation example of the terminal according
to the example embodiment;
[0035] FIG. 7 shows an operation example of the terminal according
to the example embodiment;
[0036] FIG. 8 shows an operation example of the terminal according
to the example embodiment;
[0037] FIG. 9 shows an example of a frame structure of a beacon
frame used for signaling a Responder information element by the
terminal according to the example embodiment;
[0038] FIG. 10 shows an example of a frame structure of a beacon
frame used for signaling a Responder information element by the
terminal according to the example embodiment;
[0039] FIG. 11 shows an example of a frame structure of a beacon
frame used for signaling a Responder information element by the
terminal according to the example embodiment; and
[0040] FIG. 12 shows an example of a frame structure of an iFTMR
frame and an iFTM frame used for negotiation by the terminal
according to the example embodiment.
DESCRIPTION OF EMBODIMENTS
[0041] Hereinafter, an example embodiment of the present disclosure
will be described below with reference to the drawings. The
following description and drawings are omitted and simplified as
appropriate for clarity of explanation. In the following drawings,
the same elements are denoted by the same reference signs, and
repeated description is omitted as necessary.
[0042] A configuration of a terminal 10 according to this example
embodiment will be described with reference to FIG. 4.
[0043] The terminal 10 according to a first example embodiment is,
for example, one of a plurality of terminals 10 constituting a
radio communication system of FIG. 1, and serves as either an
Initiator terminal 10I or a Responder terminal 10R. The terminal 10
according to this example embodiment may be an access point
terminal or a mobile terminal.
[0044] As shown in FIG. 4, the terminal 10 according to this
example embodiment includes a processor 11 and a memory 15. The
processor 11 includes a control unit 12, an Initiator functional
unit 13, and a Responder functional unit 14.
[0045] The processor 11 may be, for example, a microprocessor, an
MPU (Micro Processing Unit), or a CPU (Central Processing Unit).
The memory 15 is, for example, a combination of a volatile memory
and a nonvolatile memory. The processor 11 reads and executes a
software module (computer program) including instructions and data
stored in the memory 15, so that the functions of the control unit
12, the Initiator functional unit 13, and the Responder functional
unit 14 can be implemented.
[0046] The control unit 12 controls the Initiator functional unit
13 and the Responder functional unit 14. The control unit 12 uses
the Initiator functional unit 13 when controlling the terminal 10
to function as the Initiator terminal 10I, and uses the Responder
functional unit 14 when controlling the terminal 10 to function as
the Responder terminal 10R.
[0047] The Responder functional unit 14 performs the following
processing:
Processing of signaling a Responder information element indicating
that the terminal 10 is the Responder terminal 10R to a neighboring
terminal 10, Processing of negotiating with a neighboring Initiator
terminal 10I regarding an allowance of frame exchange, and
Processing of performing the FTM protocol with the Initiator
terminal 10I that has been allowed to exchange frames through
negotiation.
[0048] The Initiator functional unit 13 performs the following
processing:
Processing of discovering the neighboring Responder terminal 10R,
Processing of negotiating with the discovered Responder terminal
10R regarding an allowance of frame exchange, and Processing of
performing the FTM protocol with the Responder terminal 10R that is
allowed to exchange frames through negotiation
[0049] By the Initiator functional unit 13 performing the FTM
protocol with the Responder terminal 10R, time information (times
t1, t2, t3, and t4 in FIG. 3) and position information of the
Responder terminal 10R can be acquired, as described above.
[0050] The control unit 12 estimates an inter-terminal distance
between the terminal 10 and the Responder terminal 10R based on the
time information acquired by the Initiator functional unit 13, and
stores the estimated inter-terminal distance together with the
position information of the Responder terminal 10R in the memory
15.
[0051] Further, when the Initiator functional unit 13 performs the
FTM protocol with a plurality of Responder terminals 10R, the
control unit 12 estimates the position information of the terminal
10 based on the position information of the respective Responder
terminals 10R and the inter-terminal distances between the terminal
10 and each of the Responder terminals 10R, and stores the
estimated position information in the memory 15.
[0052] As described above, the control unit 12 uses the Initiator
functional unit 13 to control the terminal 10 to function as the
Initiator terminal 10I, and acquires the position information of
each of the neighboring Responder terminals 10R and the
inter-terminal distance between the terminal 10 and each of the
neighboring terminals 10R to thereby estimate the position
information of the terminal 10. Thus, after this, the control unit
12 can use the position information of the terminal 10 and the
Responder functional unit 14 to control the terminal 10 function as
the Responder terminal 10R.
[0053] Thus, a sufficient number of Responder terminals 10R can be
prepared in the entire radio communication system without
increasing the burden on the user. Further, since a sufficient
number of Responder terminals 10R can be prepared, it is possible
to expand the positioning coverage, which is a range in which
positioning is available by the Initiator terminal 10I.
[0054] Further, even if the position information of the terminal 10
has already been estimated, the control unit 12 uses the Initiator
functional unit 13 to control the terminal 10 to function as the
Initiator terminal 10I, so that the position information of the
terminal 10 can be re-estimated with the increased number of pieces
of the position information of each of the neighboring Responder
terminals 10R and inter-terminal distances between the terminal 10
and each of the neighboring Responder terminals 10R.
[0055] Thus, since the position information of the Responder
terminal 10R is more accurate by increasing the number of pieces of
the position information of each of the neighboring Responder
terminals 10R and the inter-terminal distances between the terminal
10 and each of the neighboring Responder terminals 10R, the
positioning accuracy can be improved on the entire radio
communication system.
[0056] As an operation of the terminal 10 according to this example
embodiment, an operation in which the terminal 10 functions as the
Initiator terminal 10I to estimate (or re-estimate) the position
information of the terminal 10 and then functions as the Responder
terminal 10R is described with reference to FIGS. 5 to 8.
[0057] First, as shown in FIG. 5, the control unit 12 uses the
Initiator functional unit 13 to control the terminal 10 to function
as the Initiator terminal 10I.
[0058] Next, the Initiator functional unit 13 discovers the
neighboring Responder terminal 10R. At this time, the Responder
terminal 10R includes a Responder information element indicating
that it is the Responder terminal 10R in a frame such as a beacon
frame and performs signaling. The details of this frame will be
described later.
[0059] The Initiator functional unit 13 discovers the Responder
terminal 10R signaling a Responder information element. Here, it is
assumed that the Initiator functional unit 13 has discovered two
Responder terminals 10R1 and 10R2.
[0060] Next, as shown in FIG. 6, the Initiator functional unit 13
first negotiates with the Responder terminal 10R1 regarding an
allowance of frame exchange from among two of the Responder
terminals 10R1 and 10R2 discovered as above. In the example of FIG.
6, although the negotiation is conducted with the Responder
terminal 10R1 first, this is only one example, and the Responder
terminal 10R that negotiates first is not particularly limited.
[0061] At this time, the Initiator functional unit 13 notifies the
Responder terminal 10R1 of a negotiation request by including it in
a frame such as a beacon frame. The Responder terminal 10R1
notifies the terminal 10 of the result of the negotiation by
including it in a frame such as a beacon frame. Details of these
frames will be described later.
[0062] When the frame exchange is allowed, the Initiator functional
unit 13 performs the FTM protocol with the Responder terminal 10R1.
By performing the FTM protocol, the Initiator functional unit 13
acquires time information (times t1, t2, t3, t4 in FIG. 3) and
position information of the Responder terminal 10R1. The control
unit 12 estimates the inter-terminal distance between the terminal
10 and the Responder terminal 10R1 based on the time information
acquired by the Initiator functional unit 13, and stores the
estimated inter-terminal distance together with the position
information of the Responder terminal 10R1 in the memory 15.
[0063] Next, as shown in FIG. 7, the Initiator functional unit 13
negotiates with the other one of the Responder terminals, which is
the Responder terminal 10R2, regarding an allowance of frame
exchange from among two of the Responder terminals 10R1 and 10R2
discovered as above. At this time, the Initiator functional unit 13
notifies the Responder terminal 10R2 of the negotiation request in
the same manner as described above. The Responder terminal 10R2
notifies the terminal 10 of the result of the negotiation in the
same manner as the Responder terminal 10R1.
[0064] When the frame exchange is allowed, the Initiator functional
unit 13 performs the FTM protocol with the Responder terminal 10R2.
By performing the FTM protocol, the Initiator functional unit 13
acquires the time information (times t1, t2, t3, t4 in FIG. 3) and
position information of the Responder terminal 10R2. The control
unit 12 estimates the inter-terminal distance between the terminal
10 and the Responder terminal 10R2 based on the time information
acquired by the Initiator functional unit 13, and stores the
estimated inter-terminal distance together with the position
information of the Responder terminal 10R2 in the memory 15.
Further, the control unit 12 estimates the position information of
the terminal 10 based on the position information of each of the
Responder terminals 10R1 and 10R2 and the inter-terminal distances
between the terminal 10 and each of the Responder terminals 10R1
and 10R2, and stores the estimated position information in the
memory 15.
[0065] After that, as shown in FIG. 8, the control unit 12 uses the
position information of the terminal 10 estimated above and the
Responder functional unit 14 to control the terminal 10 to function
as the Responder terminal 10R.
[0066] Next, the Responder functional unit 14 includes a Responder
information element indicating that the terminal 10 is the
Responder terminal 10R in a frame such as a beacon frame for
signaling to neighboring terminals 10.
[0067] Next, a frame structure of a frame used in this example
embodiment will be described. A frame structure of a frame used for
signaling the Responder information element indicative of the
Responder terminal 10R will be described with reference to FIG.
9.
[0068] For example, the Responder terminal 10R can include the
Responder information element in the beacon frame for signaling.
FIG. 9 shows the frame structure of the beacon frame at this
time.
[0069] As shown in FIG. 9, the beacon frame is composed of a MAC
(Media Access Control) header, a frame body, and an FCS (Frame
Check Sequence). The frame body includes information in units of
Elements (or Subelement).
[0070] As an example embodiment of the Responder information
element, an Element "New NGP Element" is added to the frame body of
the beacon frame shown in FIG. 9. The "New NGP Element" includes
"Element ID field", "Length field", "Status field", "Start Time
field", "Motion field", etc. Fields other than the "Status field"
from among these fields may be optionally included in the "New NGP
Element".
[0071] Here, the element indicating the status of the Responder
terminal 10R is described in the "Status field". Examples of the
element described in "Status field" are shown below.
Status:
[0072] 0: Reserved
[0073] 1: capable
[0074] 2: Incapable forever
[0075] 3: Incapable for the duration in Value field
Value:
[0076] Valid only when the Status field is set to 3
[0077] That is, when the Responder terminal 10R signals the
Responder information element, it describes in the "Status field" a
bit (or bit string) indicating the value "1" of the element.
[0078] In the "Start Time field", time information indicating the
time at which the Responder terminal 10R has estimated the position
information is described.
[0079] Since the fields other than the "Start Time field" included
in "New NGP Element" are not directly related to the present
disclosure, the description thereof is omitted.
[0080] The beacon frame used for signaling the Responder
information element is not limited to that shown in FIG. 9. The
information described in "Status field" and "QoS Field" of FIG. 9
may be replaced with beacon frames described in other Elements (or
Subelements).
[0081] For example, as shown in FIG. 10, the information described
in the "Status field" of FIG. 9 or the like may be replaced with
the beacon frame described in "NGP Element" included in an "NGP
Information field". As shown in FIG. 11, the information described
in the "Status field" in FIG. 9 or the like may be replaced with
the beacon frame included in an "Optional Subelements" and
described in the "NGP Information field". The beacon frame shown in
FIG. 11 can be used, for example, when an access point makes the
information of one or more other access points known.
[0082] A frame structure of a frame used for negotiation regarding
an allowance of frame exchange performed between the Initiator
terminal 10I and the Responder terminal 10R will be described with
reference to FIG. 12.
[0083] For example, the Initiator terminal 10I may include a
negotiation request in an iFTMR (Initial Fine Timing Measurement
Request) frame to notify the Responder terminal 10R. The Responder
terminal 10R can include the result of the negotiation in an iFTM
(Initial FTM) frame and notify the Initiator terminal 10I of the
result. FIG. 12 shows the frame structures of the iFTMR frame and
the iFTM frame at this time.
[0084] As shown in FIG. 12, the frame structure of the iFTMR frame
and the iFTM frame is the same as the frame structure of the beacon
frame shown in FIG. 10.
[0085] The Initiator terminal 10I describes a negotiation request
in the "NGP Information field" and the Responder terminal 10R
describes a result of the negotiation in the "NGP Information
field".
[0086] For example, the Responder terminal 10R describes the result
of the negotiation in the "NGP Information field" in the "Status
field". Examples of an element described in "Status field" is shown
below.
Status: 2 bits
[0087] 0: Reserved
[0088] 1: Successful
[0089] 2: Incapable forever
[0090] 3: Incapable for the duration in Value field
Value: 6 bits
[0091] Valid only when the Status field is set to 3
[0092] That is, when the Responder terminal 10R allows the exchange
of frames, it describes in the "Status field" a bit (or bit string)
indicating the value "1" of the element.
[0093] When the position information is updated, the terminal 10
stores the time information of the "Start Time field" in the beacon
frame transmitted from the Responder terminal 10R in the memory 15
in association with the position information. In a case where the
position information is updated next time, the terminal 10 compares
the time information stored by the terminal 10 in the memory 15
with the time information of the "Start Time field" in the beacon
frame transmitted from the Responder terminal 10R, and starts
negotiation with the Responder terminal 10R when the time
information of the "Start Time field" is later. However, when the
time information of the "Start Time field" is later, the terminal
10 does not need to negotiate immediately, and may determine
whether to negotiate based on moving information (amount and speed
of movement) of the terminal 10 or the frequency of
negotiation.
[0094] A sequence number may be used instead of the time
information of the "Start Time field". The terminal 10 updates the
sequence number every time the position information is updated. The
sequence number may be included in an existing information element
or may be a newly prepared information element.
[0095] As described above, according to this example embodiment,
the terminal 10 includes the Initiator functional unit 13 and the
Responder functional unit 14, and uses the Initiator functional
unit 13 to function as the Initiator terminal 10I, and estimates
the position information of the terminal 10 based on the position
information of each Responder terminal 10R and the inter-terminal
distance between the Initiator terminal 10I and each Responder
terminal 10R acquired by performing the frame exchange with the
neighboring Responder terminals 10R. After that, the terminal 10
uses the estimated position information of the terminal 10 and the
Responder functional unit 14 to function as the Responder terminal
10R.
[0096] In this manner, a sufficient number of Responder terminals
10R can be prepared in the entire radio communication system
without increasing the burden on the user. Further, since a
sufficient number of Responder terminals 10R can be prepared, it is
possible to expand the positioning coverage, which is a range in
which positioning is possible by the Initiator terminal 10I.
[0097] Further, even if the position information of the terminal 10
has already been estimated, the terminal 10 may use the Initiator
functional unit 13 to function as the Initiator terminal 10I,
re-estimate the position information of the terminal 10 based on
the position information of each of the Responder terminals 10R and
the inter-terminal distance between the Initiator terminal 10 and
each of the Responder terminals 10R acquired by performing the
frame exchange with the neighboring Responder terminals 10R, and
then use the Responder functional unit 14 to function as the
Responder terminal 10R.
[0098] In this way, since the position information of the Responder
terminal 10R is more accurate by increasing the number of pieces of
the position information of each of the neighboring Responder
terminals 10R and the inter-terminal distances between the
Initiator terminal 10 and each of the neighboring Responder
terminals 10R, the positioning accuracy can be improved in the
entire radio communication system.
[0099] Further, when the terminal 10 functions as the Responder
terminal 10R using the Responder functional unit 14, the terminal
10 may signal the Responder information element indicative of the
Responder terminal 10R to the neighboring terminals 10. Further,
when the terminal 10 functions as the Initiator terminal 10I using
the Initiator functional unit 13, the terminal 10 may discover the
neighboring Responder terminals 10R signaling the Responder
information element, and may perform the frame exchange with the
discovered Responder terminals 10R.
[0100] Thus, the terminal 10 can efficiently discover the Responder
terminal 10R while the terminal 10 functions as the Initiator
terminal 10I. Further, while the terminal 10 functions as the
Responder terminal 10R, it can efficiently inform the neighboring
terminals 10 that it is the Responder terminal 10R.
[0101] Although various aspects of the present disclosure have been
described above with reference to example embodiments, the present
disclosure is not limited by the above. The configuration and
details in each aspect of the present disclosure may be modified in
various ways as will be understood by those skilled in the art
within the scope of the disclosure.
[0102] For example, although the beacon frames are used for
signaling Responder information elements and iFTMR and iFTM frames
are used for negotiation in the example embodiment, these frames
are examples and the present disclosure is not limited to them.
[0103] Although the terminal has been described as performing the
FTM protocol based on the time information (ToA Information) in the
example embodiment, the present disclosure is not limited to them.
The present disclosure can also be applied to a radio communication
system that uses AoA (Angle of Arrival) information (Angle
Information) instead of the time information (ToA Information). In
a radio communication system using AoA information (Angle
Information), an Initiator terminal performs frame exchange with
neighboring Responder terminals and acquires position information
of each Responder terminal and AoA information (Angle Information)
indicating an angle of each Responder terminal when frame exchange
is performed. The Initiator terminal estimates the position
information of the Initiator terminal based on the position
information of each Responder terminal and the AoA information
(Angle Information) of each Responder terminal.
[0104] The above program can be stored and provided to a computer
using any type of non-transitory computer readable media.
Non-transitory computer readable media include any type of tangible
storage media. Examples of non-transitory computer readable media
include magnetic storage media (such as floppy disks, magnetic
tapes, hard disk drives, etc.), optical magnetic storage media
(e.g. magneto-optical disks), CD-ROM (Compact Disc-Read Only
Memory), CD-R (CD-Recordable), CD-R/W (CD-ReWritable), and
semiconductor memories (such as mask ROM, PROM (Programmable ROM),
EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory),
etc.).
[0105] The program may be provided to a computer using any type of
transitory computer readable media. Examples of transitory computer
readable media include electric signals, optical signals, and
electromagnetic waves. Transitory computer readable media can
provide the program to a computer via a wired communication line
(e.g. electric wires, and optical fibers) or a wireless
communication line.
[0106] The whole or part of the example embodiments disclosed above
can be described as, but not limited to, the following
supplementary notes.
Supplementary Note 1
[0107] A terminal comprising:
[0108] Initiator means for acquiring information to be used for
estimating position information of the terminal by performing frame
exchange with a neighboring Responder terminal;
[0109] Responder means for providing the information to be used for
estimating the position information of a neighboring Initiator
terminal by performing the frame exchange with the neighboring
Initiator terminal;
[0110] control means for controlling the Initiator means and the
Responder means, wherein
[0111] the control means is configured to control the terminal to
function as the Initiator terminal using the Initiator means,
estimate the position information of the terminal based on the
information acquired by controlling the terminal to exchange frames
with the neighboring Responder terminal, and then control the
terminal to function as the Responder terminal using the Responder
means and the position information.
Supplementary Note 2
[0112] The terminal according to Supplementary note 1, wherein
[0113] in a case where the terminal functions as the Responder
terminal, the control means is configured to signal a Responder
information element indicating that the terminal is the Responder
terminal to a neighboring terminal, and
[0114] in a case where the terminal functions as the Initiator
terminal, the control means is configured to: [0115] discover the
neighboring Responder terminal signaling the Responder information
element, [0116] negotiate with the discovered neighboring Responder
terminal regarding an allowance of the frame exchange, and [0117]
when the allowance is acquired, acquire the information to be used
for estimating the position information of the terminal by
performing the frame exchange with the discovered neighboring
Responder terminal.
Supplementary Note 3
[0118] The terminal according to Supplementary note 1 or 2,
wherein
[0119] the information necessary for estimating the position
information of the terminal includes the position information of
the neighboring Responder terminal and ToA (Time of Arrival)
information indicating a time when the frame exchange is performed
with the neighboring Responder terminal.
Supplementary Note 4
[0120] The terminal according to Supplementary note 3, wherein
[0121] performing the frame exchange includes performing an FTM
(Fine Time Measurement) protocol.
Supplementary Note 5
[0122] The terminal according to Supplementary note 1 or 2,
wherein
[0123] the information necessary for estimating the position
information of the terminal includes the position information of
the neighboring Responder terminal and AoA (Angle of Arrival)
information indicating an angle of the neighboring Responder
terminal when the frame exchange is performed with the neighboring
Responder terminal.
Supplementary Note 6
[0124] A radio communication system comprising:
[0125] a plurality of terminals, wherein
[0126] each terminal of the plurality of the terminals is
configured to function as either an Initiator terminal configured
to acquire information to be used for estimating position
information of the each terminal by performing frame exchange with
a neighboring Responder terminal or a Responder terminal configured
to provide the information to be used for estimating the position
information of a neighboring Initiator terminal by performing the
frame exchange with the neighboring Initiator terminal, wherein
[0127] the each terminal is configured to function as the Initiator
terminal and estimate the position information of the each terminal
based on the information acquired by performing the frame exchange
with the neighboring Responder terminal and then function as the
Responder terminal using the position information.
Supplementary Note 7
[0128] The radio communication system according to Supplementary
note 6, wherein
[0129] in a case where the each terminal functions as the Responder
terminal, the each terminal is configured to signal a Responder
information element indicating that the terminal is the Responder
terminal to a neighboring terminal, and
[0130] in a case where the each terminal functions as the Initiator
terminal, the each terminal is configured to: [0131] discover the
neighboring Responder terminal signaling the Responder information
element, [0132] negotiate with the discovered neighboring Responder
terminal regarding an allowance of the frame exchange, and [0133]
when the allowance is acquired, acquire the information to be used
for estimating the position information of the each terminal by
performing the frame exchange with the discovered neighboring
Responder terminal.
Supplementary Note 8
[0134] The radio communication system according to Supplementary
note 6 or 7, wherein
[0135] the information necessary for estimating the position
information of the each terminal includes the position information
of the neighboring Responder terminal and ToA (Time of Arrival)
information indicating a time when the frame exchange is performed
with the neighboring Responder terminal.
Supplementary Note 9
[0136] The radio communication system according to Supplementary
note 8, wherein
[0137] performing the frame exchange includes performing an FTM
(Fine Time Measurement) protocol.
Supplementary Note 10
[0138] The radio communication system according to Supplementary
note 6 or 7, wherein
[0139] the information necessary for estimating the position
information of the each terminal includes the position information
of the neighboring Responder terminal and AoA (Angle of Arrival)
information indicating an angle of the neighboring Responder
terminal when the frame exchange is performed with the neighboring
Responder terminal.
Supplementary Note 11
[0140] A communication method performed by a terminal
comprising:
[0141] controlling the terminal to function as an Initiator
terminal by estimating position information of the terminal based
on information acquired by performing frame exchange with a
neighboring Responder terminal and then controlling the terminal to
function as a Responder terminal by performing the frame exchange
with a neighboring Initiator terminal to thereby provide
information to be used for estimating the position information of
the neighboring Initiator terminal.
Supplementary Note 12
[0142] The communication method according to Supplementary note 11,
further comprising:
[0143] in a case where the terminal functions as the Responder
terminal, signaling a Responder information element indicating that
the terminal is the Responder terminal to a neighboring terminal;
and
[0144] in a case where the terminal functions as the Initiator
terminal, discovering the neighboring Responder terminal signaling
the Responder information element, negotiating with the discovered
neighboring Responder terminal regarding an allowance of the frame
exchange, and when the allowance is acquired, acquiring the
information to be used for estimating the position information of
the terminal is acquired by performing the frame exchange with the
discovered neighboring Responder terminal.
Supplementary Note 13
[0145] The communication method according to Supplementary note 11
or 12, wherein
[0146] the information necessary for estimating the position
information of the terminal includes the position information of
the neighboring Responder terminal and ToA (Time of Arrival)
information indicating a time when the frame exchange is performed
with the neighboring Responder terminal.
Supplementary Note 14
[0147] The communication method according to Supplementary note 13,
wherein
[0148] performing the frame exchange includes performing an FTM
(Fine Time Measurement) protocol.
Supplementary Note 15
[0149] The communication method according to Supplementary note 11
or 12, wherein
[0150] the information necessary for estimating the position
information of the terminal includes the position information of
the neighboring Responder terminal and AoA (Angle of Arrival)
information indicating an angle of the neighboring Responder
terminal when the frame exchange is performed with the neighboring
Responder terminal.
[0151] This application is based upon and claims the benefit of
priority from Japanese patent application No. 2018-080308, filed on
Apr. 19, 2018, the disclosure of which is incorporated herein in
its entirety by reference.
REFERENCE SIGNS LIST
[0152] 10 TERMINAL
[0153] 10I, 10I1 INITIATOR TERMINAL
[0154] 10R, 10R1 TO 10R4 RESPONDER TERMINAL
[0155] 11 PROCESSOR
[0156] 12 CONTROL UNIT
[0157] 13 INITIATOR FUNCTIONAL UNIT
[0158] 14 RESPONDER FUNCTIONAL UNIT
[0159] 15 MEMORY
* * * * *
References