U.S. patent application number 14/629671 was filed with the patent office on 2015-06-18 for method and a device for reporting the number of correctly decoded transport blocks in a wireless system.
The applicant listed for this patent is Core Wireless Licensing S.A.R.L.. Invention is credited to Harri Aatos Jokinen, Benoist Pierre Sebire.
Application Number | 20150172933 14/629671 |
Document ID | / |
Family ID | 29558641 |
Filed Date | 2015-06-18 |
United States Patent
Application |
20150172933 |
Kind Code |
A1 |
Sebire; Benoist Pierre ; et
al. |
June 18, 2015 |
METHOD AND A DEVICE FOR REPORTING THE NUMBER OF CORRECTLY DECODED
TRANSPORT BLOCKS IN A WIRELESS SYSTEM
Abstract
A method and a device for reporting the number of correctly
decoded transport blocks in a wireless system. The maximum number
of correctly decoded transport blocks within a reporting period is
determined. Then the actual number of correctly decoded transport
blocks is determined and cultivated into an indication thereof on
the basis of the maximum number. The indication is sent to a
network element capable of decoding it for analysis.
Inventors: |
Sebire; Benoist Pierre;
(Tokyo, JP) ; Jokinen; Harri Aatos; (Pertteli,
FI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Core Wireless Licensing S.A.R.L. |
Plano |
TX |
US |
|
|
Family ID: |
29558641 |
Appl. No.: |
14/629671 |
Filed: |
February 24, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13669642 |
Nov 6, 2012 |
8982821 |
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14629671 |
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10579602 |
Feb 2, 2007 |
8310933 |
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PCT/FI2004/000685 |
Nov 16, 2004 |
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13669642 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04L 1/206 20130101;
H04W 28/04 20130101; H04L 29/06 20130101; H04L 1/203 20130101; H04L
69/32 20130101; H04L 1/0072 20130101; H04W 28/0205 20130101; H04L
1/0075 20130101; H04L 1/0061 20130101; H04W 24/00 20130101 |
International
Class: |
H04W 24/00 20060101
H04W024/00; H04W 28/04 20060101 H04W028/04; H04W 28/02 20060101
H04W028/02; H04L 1/00 20060101 H04L001/00 |
Claims
1. A method for a wireless system adapted to transfer data in radio
packets over an interface, the method comprising: obtaining
information about a maximum number of correctly decoded transport
blocks during a reporting period, obtaining a number of correctly
decoded transport blocks during the reporting period, adapting an
indication about the number of correctly decoded transport blocks
during the reporting period into a transferable form on the basis
of the obtained information about the maximum number of correctly
decoded transport blocks during the reporting period, wherein the
adapting comprises truncation of at least one bit of a binary
representation of the number of correctly decoded transport blocks
during the reporting period, and sending the indication about the
number of correctly decoded transport blocks during the reporting
period over the interface.
2. The method of claim 1, wherein the maximum number of correctly
decoded transport blocks is determined on the basis of transport
blocks in which a cyclic redundancy check is used.
3. The method of claim 1, wherein the maximum number of correctly
decoded transport blocks is determined on the basis of transport
blocks associated with active transport channels.
4. The method of claim 1, wherein only a subset of all transport
channels in a transport format combination set is taken into
account.
5. The method of claim 1, wherein the maximum number of correctly
decoded transport blocks is determined on the basis of the maximum
number of active transport channels in a transport format
combination of a transport format combination set on a dedicated
physical subchannel.
6. The method of claim 1, wherein at least one transport format
combination for signalling is omitted from both the maximum number
of correctly decoded transport blocks during the reporting period
and the number of correctly decoded transport blocks during the
reporting period.
7. The method of claim 1, wherein in obtaining the number of
correctly decoded transport blocks during the reporting period only
the transport blocks in which a cyclic redundancy check is used are
counted in, the counted in transport blocks considered as correctly
decoded according to the cyclic redundancy check thereof.
8. The method of claim 1, wherein in obtaining the number of
correctly decoded transport blocks during the reporting period all
the received transport blocks are considered as correctly decoded
provided that there is no transport format combination in a
transport format combination set comprising at least one active
transport channel utilizing a cyclic redundancy check.
9. The method of claim 1, wherein the non-linear reporting scale is
higher for a range within the limited range where all blocks are
sent and a low number of blocks are incorrectly decoded.
10. The method of claim 1, wherein the system utilizes a flexible
layer one in data transfer.
11. The method of claim 1, wherein the non-linear reporting scale
is higher for a range within the limited range where only a few
correct blocks are correctly decoded.
12. The method of claim 1, wherein the indication is sent in a nbr
rcvd block parameter.
13. The method of claim 1, wherein the reporting period is a slow
associated control channel reporting period, and the slow
associated control channel is the channel on which the indication
is transferred.
14. An apparatus operable in a system adapted to transfer data in
packets over an interface, the apparatus comprising a processing
unit and a memory comprising a computer program code, the memory
and the computer program code configured to, with the processing
unit, cause the apparatus to perform at least the following: obtain
information about a maximum number of correctly decoded transport
blocks during a reporting period; obtain a number of correctly
decoded transport blocks during the reporting period; adapt an
indication about the number of correctly decoded transport blocks
during the reporting period into a transferable form on the basis
of the obtained information about the maximum number of correctly
decoded transport blocks during the reporting period, wherein the
adapting comprises truncation of at least one bit of a binary
representation of the number of correctly decoded transport blocks
during the reporting period, and send the indication about the
number of correctly decoded transport blocks during the reporting
period over the interface.
15. The apparatus of claim 14, wherein the non-linear reporting
scale is higher for a range within the limited range where only a
few correct blocks are correctly decoded.
16. The apparatus of claim 14, adapted to determine the maximum
number of correctly decoded transport blocks based on the maximum
number of active transport channels in a transport format
combination of a transport format combination set on a dedicated
physical subchannel.
17. The apparatus of claim 14, adapted to take into account only
the transport blocks utilizing a cyclic redundancy check in the
maximum number of correctly decoded transport blocks during the
reporting period.
18. The apparatus of claim 14, adapted to omit at least one
transport format combination for signalling from both the maximum
number of correctly decoded transport blocks during the reporting
period and the number of correctly decoded transport blocks during
the reporting period.
19. The apparatus of claim 14, adapted to consider the transport
blocks as correctly decoded according to the cyclic redundancy
check.
20. The apparatus of claim 14, adapted to consider the received
transport blocks as correctly decoded provided that there is no
transport format combination in a transport format combination set
including at least one active transport channel utilizing a cyclic
redundancy check.
21. The apparatus of claim 14 that is a mobile terminal.
22. The apparatus of claim 14 that utilizes a flexible layer one in
data reception.
23. The apparatus of claim 14 wherein the non-linear reporting
scale is higher for a range within the limited range where all
blocks are sent and a low number of blocks are incorrectly
decoded.
24. The apparatus of claim 14 that utilizes a slow associated
control channel to sent the indication.
25. An apparatus operable in a system adapted to transfer data in
packets over an interface, the apparatus comprising a processing
unit and a memory comprising a computer program code, the memory
and the computer program code configured to, with the processing
unit, cause the apparatus to perform at least the following: obtain
information about a maximum number of correctly decoded transport
blocks during a reporting period, obtain a number of correctly
decoded transport blocks during the reporting period, adapt an
indication about the number of correctly decoded transport blocks
during the reporting period into a transferable form on the basis
of the obtained information about the maximum number of correctly
decoded transport blocks during the reporting period, wherein the
adapting comprises truncation of at least one bit of a binary
representation of the number of correctly decoded transport blocks
during the reporting period, and send the indication about the
number of correctly decoded transport blocks during the reporting
period over the interface.
26. The apparatus of claim 25 wherein the non-linear reporting
scale is higher for a range within the limited range where only a
few correct blocks are correctly decoded.
27. The apparatus of claim 25 wherein the non-linear reporting
scale is higher for a range within the limited range where all
blocks are sent and a low number of blocks are incorrectly
decoded.
28. The apparatus of claim 25, adapted to receive the indication on
a slow associated control channel.
29. A non-transitory medium tangibly encoded with a computer
executable program configured to execute, when the computer
executable program is run by a processor, a method for a system
adapted to transfer data in packets over an interface with
instructions that, when executed by the processor, perform:
obtaining information about a maximum number of correctly decoded
transport blocks during a reporting period at the latest when the
reporting period has expired, obtaining a number of correctly
decoded transport blocks during the reporting period, adapting an
indication about the number of correctly decoded transport blocks
into a transferable form based on the obtained information about
the maximum number of correctly decoded transport blocks, wherein
the adapting comprises selecting a binary representation of the
number of correctly decoded transport blocks during the reporting
period from a non-linear mapping table that maps the number of
correctly decoded transport blocks to a limited range of numbers in
a non-linear reporting scale of resolution for the binary
representation with the reporting scale higher for selected numbers
in the limited range, and sending the indication over the
interface.
30. A method for a system adapted to transfer data in packets over
an interface, the method comprising: obtaining information about a
maximum number of correctly decoded transport blocks during a
reporting period at the latest when the reporting period has
expired, obtaining a number of correctly decoded transport blocks
during the reporting period, adapting an indication about the
number of correctly decoded transport blocks into a transferable
form based on the obtained information about the maximum number of
correctly decoded transport blocks, wherein the adapting comprises
selecting a binary representation of the number of correctly
decoded transport blocks during the reporting period from a
non-linear mapping table that maps the number of correctly decoded
transport blocks to a limited range of numbers in a non-linear
reporting scale of resolution for the binary representation with
the reporting scale higher for selected numbers in the limited
range, and sending the indication over the interface.
31. The method of claim 30, wherein the non-linear reporting scale
is higher for a range within the limited range where all blocks are
sent and a low number of blocks are incorrectly decoded.
32. The method of claim 30, wherein the non-linear reporting scale
is higher for a range within the limited range where only a few
correct blocks are correctly decoded.
33. A non-transitory medium tangibly encoded with a computer
executable program configured to execute, when the computer
executable program is run by a processor, a method for a system
adapted to transfer data in packets over an interface with
instructions that, when executed by the processor, perform:
obtaining information about a maximum number of correctly decoded
transport blocks during a reporting period at the latest when the
reporting period has expired, obtaining a number of correctly
decoded transport blocks during the reporting period, adapting an
indication about the number of correctly decoded transport blocks
into a transferable form based on the obtained information about
the maximum number of correctly decoded transport blocks, wherein
the adapting comprises selecting a binary representation of the
number of correctly decoded transport blocks during the reporting
period from a non-linear mapping table that maps the number of
correctly decoded transport blocks to a limited range of numbers in
a non-linear reporting scale of resolution for the binary
representation with the reporting scale higher for selected numbers
in the limited range, and sending the indication over the
interface.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 13/669,642 filed Nov. 6, 2012, which is a continuation of U.S.
application Ser. No. 10/579,602, filed Feb. 2, 2007, now U.S. Pat.
No. 8,310,933, filed as Application No. PCT/FI04/00685 on Nov. 16,
2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to communication
systems. In particular the invention concerns GERAN (GSM/EDGE Radio
Access Network) radio access network and air interface thereof in
which a special type of physical layer called flexible layer one
(FLO) is utilized.
BACKGROUND OF THE INVENTION
[0003] Modern wireless communication systems such as GSM (Global
System for mobile communications) and UMTS (Universal Mobile
Telecommunications System) are capable of transferring various
types of data over the air interface between the network elements
such as a base station and a mobile station (MS). As the general
demand for transfer capacity continuously rises due to e.g. new
multimedia services coming available, new more efficient techniques
have been developed in order to exploit the existing resources to a
maximum extent.
[0004] A technical report 3GPP 45.902 [1] discloses a concept of
flexible layer one, a new physical layer proposed for the GERAN.
The ingenuity of the concept relies on the fact that the
configuration of the physical layer including e.g. channel coding
and interleaving is specified not until the call set-up. Thus, the
support of new services can be handled smoothly without having to
specify new coding configuration schemes separately in connection
with each release.
[0005] Development work of the FLO concept has been provided with
somewhat strict requirements. FLO should, for example, support
multiplexing of parallel data flows on to a basic physical
subchannel and provide optimisation of spectral efficiency through
the support of different interleaving depths, unequal error
protection/detection, reduced channel coding rate granularity and
support of different (8 PSK, GMSK etc) modulations. Moreover, the
solution shall be future proof and minimize the overhead introduced
by the radio protocol stack.
[0006] According to the GERAN Release 5 the MAC sublayer (Layer 2
for FLO) handles the mapping between the logical channels (traffic
or control) and the basic physical subchannels introduced in 3GPP
TS 45.002 [2].
[0007] In UTRAN (UMTS Radio Access Network), the MAC utilizes
so-called Transport Channels TrCH for transferring data flows with
given QoS's (Quality of Service) over the air interface. As a
result, several transport channels, that are configured at call
set-up, can be active at the same time and be multiplexed at the
physical layer.
[0008] Now, by adopting the idea of FLO, aforesaid flexible
transport channels can be utilized in GERAN as well. Accordingly,
the physical layer of GERAN may offer one or several transport
channels to the MAC sublayer. Each of these transport channels can
carry one data flow providing a certain Quality of Service (QoS). A
number of transport channels can be multiplexed and sent on the
same basic physical subchannel at the same time.
[0009] The configuration of a transport channel i.e. the number of
input bits, channel coding, interleaving etc. is denoted as a
Transport Format (TF). Furthermore, a number of different transport
formats can be associated to a single transport channel. The
configuration of the transport formats is completely controlled by
the RAN (Radio Access Network) and signalled to the MS at call
set-up. Correct interpretation of the TF is crucial at the
receiving end as well as the transport format defines the utilized
configuration for decoding of the data. When configuring a
transport format, the RAN can, for example, choose between a number
of predefined CRC (Cyclic Redundancy Check) lengths and block
lengths.
[0010] On transport channels, transport blocks (TB) are exchanged
between the MAC sublayer and the physical layer on a transmission
time interval (TTI) basis. For each TTI a transport format is
chosen and indicated through the transport format indicator (TFIN).
In other words, the TFIN tells which transport format to use for
that particular transport block on that particular TrCH during that
particular TTI. When a transport channel is inactive, the transport
format with a transport block size of zero (empty transport format)
is selected.
[0011] Only a limited number of combinations of the transport
formats of the different transport channels are allowed. A valid
combination is called a Transport Format Combination (TFC). The set
of valid TFCs on a basic physical subchannel is called a Transport
Format Combination Set (TFCS). The TFCS is signalled through
Calculated Transport Format Combinations (CTFC).
[0012] In order to decode a received sequence the receiver needs to
know the active TFC for the radio packet. This information is
transmitted in the Transport Format Combination Identifier (TFCI)
field. Aforesaid field is basically a layer 1 header and has the
same function as the stealing bits in GSM. Each of the TFC within a
TFCS is assigned a unique TFCI value and upon receipt of a radio
packet this is the first element to be decoded by the receiver. By
exploiting the decoded TFCI value the transport formats for the
different transport channels can be determined and the actual
decoding can start.
[0013] In case of multislot operation, there shall be one FLO
instance for each basic physical subchannel. Each FLO instance is
configured independently by Layer 3 and gets an own TFCS as a
result. The number of allocated basic physical subchannels depends
on the multislot capabilities of the MS.
[0014] For the time being the use of FLO is planned to be limited
to dedicated channels only, thus maintaining the 26-multiframe
structure for which the SACCH (Slow Associated Control Channel)
shall be treated as a separate logical channel based on GERAN
Release 5.
[0015] The concept of transport formats and channels as presented
in reference [1] is visualized in FIG. 1 where e.g. coded speech is
to be transmitted over FLO. Speech is transferred by using three
different modes MODE 1, MODE 2, MODE 3 with different bit rates and
an additional comfort noise generation mode CNG MODE. Inside a mode
the speech bits have been divided into three different classes
represented by three transport channels TrCHA 102, TrCHB 104, and
TrCHC 106 on the basis of their varying importance during the
speech reconstruction stage, for example. Numbers inside the
blocks, see e.g. the block pointed by legend 108, being arbitrary
in this example though, indicate the required number of bits in a
transport channel and codec mode specific manner. Hence, it can be
noticed from the figure that TrCHA contains four transport formats
(0, 60, 40, 30), TrCHB three transport formats (0, 20, 40) and
TrCHC only two formats (0, 20). Resulting transport format
combinations TFC1-TFC4, that refer to transport formats on
different channels that can be active at the same time, are
depicted with dotted lines in the figure. All these valid
combinations constitute the TFCS that is signalled through CTFC. An
example of CTFC determination is found in reference [1] in addition
to techniques applicable in proper TFC selection.
[0016] A protocol architecture of FLO in case of Iu mode is
depicted in FIG. 2 wherein MAC layer 208 maps either a plurality of
logical channels or TBFs (temporary block flows) from RLC entities
located in RLC layer 206, said RLC layer 206 receiving data from
e.g. PDCP 204 (Packet Data Convergence Protocol) and controlled by
RRC (Radio Resource Controller) 202, to physical layer 210. In
current specification [1] logical channels are used but are
presumably to be replaced with the concept of temporary block flows
in the future. TBF concept is described in reference [3] in more
detail. A dedicated channel (DCH) can be used as a transport
channel dedicated to one MS in uplink or downlink direction. Three
different DCHs have been introduced: CDCH (Control-plane DCH), UDCH
(User-plane DCH) and ADCH (Associated DCH), the CDCH and UDCH of
which used for transmission of RLC/MAC data transfer blocks,
whereas the ADCH targeted for transmission of RLC/MAC control
blocks. A mobile station may concurrently have a plurality of
transport channels active.
[0017] The FLO architecture is illustrated in FIG. 3 especially in
relation to Layer 1 for FLO. In this version only a one-step
interleaving has been assumed, i.e. all transport channels on one
basic physical subchannel have the same interleaving depth. An
alternative architecture with two-step interleaving is disclosed in
reference [1] for review. Basic error detection is carried out with
a cyclic redundancy check. A Transport Block is inputted to error
detection 302 that utilizes a selected generator polynomial in
order to calculate the checksum to be attached to the block. Next,
the updated block called Code Block is fed into a convolutional
channel coder 304 introducing additional redundancy to it. In rate
matching 306 bits of an Encoded Block are either repeated or
punctured. As the block size can vary, also the number of bits on a
transport channel may correspondingly fluctuate. Thereupon, bits
shall be repeated or punctured in order to keep the overall bit
rate in line with the actual allocated bit rate of the
corresponding sub-channel. Output from rate matching block 306 is a
called a Radio Frame. Transport channel multiplexing 308 takes care
of multiplexing of Radio Frames from active transport channels
TrCH(i) . . . TrCH(1) received from matching block 306 into a
CCTrCH (Coded Composite Transport Channel). In TFCI mapping 310 a
TFCI is constructed for the CCTrCH. The size of the TFCI depends on
the number of TFCs needed. The size should be minimized in order to
avoid unnecessary overhead over the air interface. For example, a
TFCI of 3 bits can indicate 8 different transport format
combinations. If these are not enough, a dynamic connection
reconfiguration is needed to be performed. The TFCI is (block)
coded and then interleaved 312 with CCTrCH (these two constituting
a Radio Packet) on bursts. The selected interleaving technique is
configured at call set-up.
[0018] RRC layer, Layer 3 for FLO, manages set-up, reconfiguration
and release of the traffic channels. Upon creating a new
connection, Layer 3 indicates to the lower layers various
parameters to configure the physical, MAC and RLC layers.
Parameters include the transport channel identity (TrCH Id) and
transport format set for each transport channel, transport format
combination set through CTFC with modulation parameter etc. In
addition, Layer 3 provides transport channel specific parameters
such as CRC size, rate matching parameters, transport format
dynamic attributes etc. The transport channels and the transport
format combination set are separately configurable in the uplink
and downlink directions by utilizing e.g. Radio Bearer procedures
disclosed in sections 7.14.1 and 7.19 of reference [4] in more
detail.
[0019] Furthermore, Layer 3 may include information about transport
format combination subset(s) to further restrict the use of
transport format combinations within the TFCS. Such information may
be formed via a "minimum allowed transport format combination
index", an "allowed transport format combination list", a
"non-allowed transport formation combination list" etc.
[0020] Clearly also incremental TFCS reconfiguration should be
possible in FLO, i.e. information only about transport channels or
TFCs that are added, modified or deleted could be signalled by e.g.
modified Radio Bearer signalling. After various reconfigurations,
the overall configuration should still be consistent, which could
be assured by, for example, removing all TFCs from the TFCS that
utilize a transport channel to be released.
[0021] Current specifications [4], [5], and [6] concerning link
control and especially RRC protocol in GERAN describe how, in
connection with enhanced measurement reporting, the terminal
reports on the SACCH to the network the number of correctly decoded
blocks with NBR_RCVD_BLOCKS parameter embedded in ENHANCED
MEASUREMENT REPORT message. The network may then assess the block
error rate (BLER) after decoding. On one DBPSCH, the maximum number
of blocks within a SACCH reporting period is normally 24. Likewise,
the maximum value of the number of correctly decoded blocks is 24,
and an unambiguous binary representation thereof requires 5 bits,
i.e. 25=32 (>24), in which case 8 values are in principle left
unused.
[0022] Due to the adoption of FLO in GERAN, a maximum of 24 radio
packets can be received during a SACCH reporting period but every
radio packet may contain up to four transport blocks, according to
the current consensus, and thus, a total of 24.times.4 transport
blocks may be correctly decoded during a SACCH reporting period.
This is derived from the present limitation set for FLO
requirements according to which the FLO shall support a maximum of
4 active transport channels (->transport blocks) per radio
packet per basic physical subchannel. Therefore the already fixed
five bits for a NBR_RCVD_BLOCKS parameter is not enough for
unequivocally representing the number of (correctly) decoded
blocks. Although new messages and parameters could be defined to
overcome the need for a lengthened parameter, such modifications
are not preferred as they require changes both to a number of
specifications and to devices (terminals and network elements)
actually following those, and, in addition, increase the amount of
data transmitted over the air interface.
SUMMARY OF THE INVENTION
[0023] The object of the present invention is to enable reporting
of the number of correctly decoded transport blocks in a wireless
system using the FLO or corresponding concept without increasing
the overhead over the air interface. The object is achieved by
utilizing the aforesaid actual existing reporting procedure as to
the actual message definition, parameters, and parameter sizes.
However, the meaning of bits in the NBR_RCVD_BLOCKS parameter is
updated to change adaptively depending on the maximum number of
correctly decoded transport blocks during a reporting period. In a
basic solution of the invention the least significant bits (LSB) of
the binary representation of the number of correctly decoded blocks
are truncated whenever needed in order to fit said representation
to the fixed number of bits (5) in the NBR_RCVD_BLOCKS parameter.
Also other additional or alternative mappings between the original
representation and the parameter can be used. E.g. a non-linear
reporting scale may be exploited to change the reporting resolution
according to the number of correctly decoded blocks.
[0024] The utility of the invention is based on a plurality of
issues. First, the existing procedures for sending and receiving
the reporting information are still applicable and changes to
message/parameter structures/sizes are not required. Secondly, the
resolution on which the number of correctly received blocks is
reported is adaptive; it can be adjusted to provide a finer grid in
some specific scenarios related to some particular number (range)
of received blocks or to generally degrade when the maximum number
of received blocks increases. Furthermore, the provided solution is
somewhat straightforward to implement and does not substantially
require more processing power or memory space in the executing
device than the prior art technique. Additional signalling between
the ends of a connection is not required for utilizing the
invention.
[0025] According to the invention, a method for reporting the
number of correctly decoded transport blocks in a wireless system
adapted to transfer data in radio packets over the air interface
thereof, where a number of transport blocks associated with a
number of transport channels are included in a radio packet and a
number of packets received during a reporting period, is
characterized in that it has the steps of
[0026] obtaining information about the maximum number of correctly
decoded transport blocks during the reporting period,
[0027] obtaining the number of correctly decoded transport blocks
during the reporting period,
[0028] adapting an indication about said number of correctly
decoded transport blocks during the reporting period on the basis
of the obtained information, and
[0029] sending said indication about said number of correctly
decoded transport blocks during the reporting period.
[0030] In another aspect of the invention, a device operable in a
wireless system adapted to receive a number of transport blocks
included in a radio packet, a number of radio packets received
during a reporting period, said device comprising processing means
and memory means configured to process and store instructions and
data, and data transfer means configured to transfer data, is
characterized in that it is adapted to obtain information about the
maximum number of correctly decoded transport blocks during the
reporting period, obtain the number of correctly decoded transport
blocks during the reporting period, adapt an indication about said
number of correctly decoded transport blocks during the reporting
period on the basis of the obtained information, and to send said
indication about said number of correctly decoded transport blocks
during the reporting period.
[0031] In a further aspect of the invention, a device operable in a
wireless system adapted to transfer data in radio packets over the
air interface thereof, a number of transport blocks included in a
radio packet and a number of radio packets transferred during a
reporting period, said device comprising processing means and
memory means configured to process and store instructions and data,
and data transfer means configured to transfer data, is
characterized in that it is adapted to obtain information about the
maximum number of transport blocks transferred to a terminal during
the reporting period, receive an indication about the number of
correctly decoded transport blocks during the reporting period by
the terminal, and to, on the basis of the information obtained and
the indication received, determine the actual number of correctly
decoded transport blocks.
[0032] The term "adapting" refers herein especially to fitting an
indication into a transferable form according to the obtained
information. Moreover, also some other issues such as a predefined
data field length, in addition to the obtained information, may
affect the adaptation. For example, if the indication is an
adaptively truncated binary representation of the corresponding
number like in the basic solution of the invention, both the
maximum possible numeric range (maximum number of correctly
received blocks) and the predefined length of the indication
parameter to be sent determine the final form of the
indication.
[0033] In one embodiment of the invention, a mobile terminal
exploits the proposed method for reporting the number of correctly
decoded transport blocks during a reporting period. The mobile
terminal determines on the basis of the maximum number of decoded
transport blocks a proper indication model and, accordingly,
transmits a parameter indicating the measured number of correctly
decoded blocks to the network. A network element then receives the
parameter and decodes it on the basis of information available
about the maximum number of transport blocks transferred during the
reporting period.
[0034] Dependent claims disclose embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Hereinafter the invention is described in more detail by
reference to the attached drawings, wherein
[0036] FIG. 1 discloses a visualization of a TFCS structure.
[0037] FIG. 2 illustrates FLO protocol architecture in GERAN Iu
mode.
[0038] FIG. 3 illustrates FLO architecture.
[0039] FIG. 4A is a signalling chart of the embodiment of the
invention.
[0040] FIG. 4B is a visualization of a scenario in which six TFCs
and three transport channels are included in a TFCS.
[0041] FIG. 4C is a visualization of a corresponding scenario with
five TFCs and four transport channels instead.
[0042] FIG. 5 discloses a flow diagram of the method of the
invention.
[0043] FIG. 6 discloses a block diagram of a device adapted to
utilize the invention.
DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION
[0044] FIGS. 1, 2, and 3 were already discussed in conjunction with
the description of related prior art.
[0045] FIG. 4A discloses, by way of example only, a signalling
chart describing the scenario of the embodiment of the invention in
which mobile terminal 402 receives radio packets from network 404.
Radio packets 406, 408, and 410 are received during a reporting
period indicated by reference sign 422. Terminal 402 decodes 414,
416, and 418 the block(s) included in the packets, which may mean,
for example, simple reception and demodulation of data into
exploitable form or, if a CRC is used in the block(s), more
sophisticated comparison of (re)calculated CRC value with its
received counterpart.
[0046] After receiving (and decoding) the blocks included in the
packets during the reporting period terminal 402 determines 420 the
number of correctly decoded blocks within the period, adapts an
indication thereof and reports 412 the indication to network 404.
Network 404 determines 424 said number on the basis of the received
indication and knowledge about the current TFC structure (maximum
number of decoded blocks during a reporting period with possible
additional conditions, explained hereinafter).
[0047] In order to keep existing messages as they are (with a 5
bits NBR_RCVD_BLOCKS parameter), the least significant bit(s) of
the binary representation of the number of correctly decoded
transport blocks can be truncated. The result is then mapped to
NBR_RCVD_BLOCKS.
[0048] The number of truncated LSBs depends on the maximum number
of correctly decoded transport blocks during a SACCH reporting
period; such maximum can be indicated via e.g. NbTBmax
parameter.
[0049] To further expand on the concept of NbTBmax and considering
especially a SACCH reporting period, a maximum of 24 radio packets
can be received. Then the maximum number of transport blocks that
can be correctly decoded in a radio packet depends on the TFCS of
the DBPSCH. NbTBmax can be calculated as
[0050] NbTBmax=24.times. (the maximum number of active transport
channels in a TFC of the TFCS of the DBPSCH),
[0051] where transport channel is basically considered as active in
a particular TFC if it carries a transport block that really is
transferred, i.e. the size of which is >0. Notation x denotes
multiplication. Possibly some supplementary conditions are also
used for further determining the NbTBmax parameter. For example,
only the transport blocks (transport channels) for which a CRC is
used (refer to CODE BLOCK in FIG. 3) may be included in the
NbTBmax. On the other hand, signalling TFC, being e.g. the first
TFC with e.g. TFCI=0, may be excluded from the NbTBmax
calculations.
[0052] FIG. 4B depicts an example of an TFCS where six TFCs are
defined for FLO on a DBPSCH. In this example, it is assumed that
only transport channel A and transport channel C use a CRC. The
maximum number of active transport channel for which a CRC is used
in a TFC is therefore 1. Consequently, NbTBmax=24.times.1=24.
[0053] FIG. 4C depicts another example of TFCS where five TFCs are
defined for FLO on a DBPSCH. In this example, it is assumed that
all transport channels A, B, C and D use a CRC. The maximum number
of active transport channel for which a CRC is used in a TFC is
therefore 3 (TFC 5). Consequently, NbTBmax=24.times.3=72.
[0054] Once NbTBmax is known, the number of bits that need to be
truncated from the 5 bit binary representation of the number of
correctly decoded transport blocks can easily be calculated
according to Table 1 below.
TABLE-US-00001 TABLE 1 NbTBmax Truncation 0-31 None - direct binary
representation possible 32-63 1 LSB - See Table 2 64-96 2 LSB - See
Table 3
[0055] Since the number of LSB to be truncated can be calculated by
the terminal from the TFCS it receives from the network at call
setup, there is no need to explicitly signal it, although it can be
done via e.g. a separate parameter in a new/existing message. Both
ends know the TFCS and both ends know how many bits are truncated
from the binary representation of the number of correctly decoded
transport blocks (0, 1 or 2) to fit in NBR_RCVD_BLOCKS.
[0056] Additionally, at call set-up for example, the network may
order the terminal (by sending a request etc) to take into account
only a subset of the transport channels. For instance in FIG. 4C,
the network may tell the terminal to monitor the decoding success
on channels TrCH A and B. The maximum number of active transport
channel (A and/or B) in a TFC is then 2. Consequently,
NbTBmax=24.times.2=48 and 1 bit truncation is required (see Table
1).
[0057] Corresponding to the determination of NbTBmax, counting of
the effective number of correctly decoded transport blocks utilizes
similar principles. Blocks in a signalling TFC may not be regarded
to be included in said number. For instance in FIG. 4B and FIG. 4C,
the first TFC (TFC1 with e.g. TFCI=0) can be reserved for
signalling. Moreover, transport blocks can be considered as
correctly decoded according to the CRC received. If there is no CRC
in a block, however, the block is not counted either unless the
TFCS (possibly excluding the signalling TFC) does not contain a TFC
for which at least one transport channel that uses a CRC is active,
in which case all received transport blocks may be considered as
correctly decoded. Hence, CRC may be exploited whenever available,
otherwise counting is based on reception only, for example.
[0058] See Tables 2 and 3 depicting truncation of 1 and 2 LSBs
respectively.
TABLE-US-00002 TABLE 2 Truncation of the LSB bit 6 bit 5 bit 4 bit
3 bit 2 Received NBR_RCVD_BLOCKS Blocks bit 5 bit 4 bit 3 bit 2 bit
1 bit 1 0 or 1 0 0 0 0 0 0 or 1 2 or 3 0 0 0 0 1 0 or 1 4 or 5 0 0
0 1 0 0 or 1 6 or 7 0 0 0 1 1 0 or 1 8 or 9 0 0 1 0 0 0 or 1 10 or
11 0 0 1 0 1 0 or 1 12 or 13 0 0 1 1 0 0 or 1 14 or 15 0 0 1 1 1 0
or 1 16 or 17 0 1 0 0 0 0 or 1 18 or 19 0 1 0 0 1 0 or 1 20 or 21 0
1 0 1 0 0 or 1 22 or 23 0 1 0 1 1 0 or 1 24 or 25 0 1 1 0 0 0 or 1
26 or 27 0 1 1 0 1 0 or 1 28 or 29 0 1 1 1 0 0 or 1 30 or 31 0 1 1
1 1 0 or 1 32 or 33 1 0 0 0 0 0 or 1 34 or 35 1 0 0 0 1 0 or 1 36
or 37 1 0 0 1 0 0 or 1 38 or 39 1 0 0 1 1 0 or 1 40 or 41 1 0 1 0 0
0 or 1 42 or 43 1 0 1 0 1 0 or 1 44 or 45 1 0 1 1 0 0 or 1 46 or 47
1 0 1 1 1 0 or 1 48 or 49 1 1 0 0 0 0 or 1 50 or 51 1 1 0 0 1 0 or
1 52 or 53 1 1 0 1 0 0 or 1 54 or 55 1 1 0 1 1 0 or 1 56 or 57 1 1
1 0 0 0 or 1 58 or 59 1 1 1 0 1 0 or 1 60 or 61 1 1 1 1 0 0 or 1 62
or 63 1 1 1 1 1 0 or 1
TABLE-US-00003 TABLE 3 Truncation of 2 LSBs bit 7 bit 6 bit 5 bit 4
bit 3 Received NBR_RCVD_BLOCKS Blocks bit 5 bit 4 bit 3 bit 2 bit 1
bit 2 bit 1 0, 1, 2 or 3 0 0 0 0 0 0 or 1 0 or 1 4, 5, 6 or 7 0 0 0
0 1 0 or 1 0 or 1 8, 9, 10 or 11 0 0 0 1 0 0 or 1 0 or 1 12, 13, 14
or 15 0 0 0 1 1 0 or 1 0 or 1 16, 17, 18 or 19 0 0 1 0 0 0 or 1 0
or 1 20, 21, 22 or 23 0 0 1 0 1 0 or 1 0 or 1 24, 25, 26 or 27 0 0
1 1 0 0 or 1 0 or 1 28, 29, 30 or 31 0 0 1 1 1 0 or 1 0 or 1 32,
33, 34 or 35 0 1 0 0 0 0 or 1 0 or 1 36, 37, 38 or 39 0 1 0 0 1 0
or 1 0 or 1 40, 41, 42 or 43 0 1 0 1 0 0 or 1 0 or 1 44, 45, 46 or
47 0 1 0 1 1 0 or 1 0 or 1 48, 49, 50 or 51 0 1 1 0 0 0 or 1 0 or 1
52, 53, 54 or 55 0 1 1 0 1 0 or 1 0 or 1 56, 57, 58 or 59 0 1 1 1 0
0 or 1 0 or 1 60, 61, 62 or 63 0 1 1 1 1 0 or 1 0 or 1 64, 65, 66
or 67 1 0 0 0 0 0 or 1 0 or 1 68, 69, 70 or 71 1 0 0 0 1 0 or 1 0
or 1 72, 73, 74 or 75 1 0 0 1 0 0 or 1 0 or 1 76, 77, 78 or 79 1 0
0 1 1 0 or 1 0 or 1 80, 81, 82 or 83 1 0 1 0 0 0 or 1 0 or 1 84,
85, 86 or 87 1 0 1 0 1 0 or 1 0 or 1 88, 89, 90 or 91 1 0 1 1 0 0
or 1 0 or 1 92, 93, 94 or 95 1 0 1 1 1 0 or 1 0 or 1 96, 97, 98 or
99 1 1 0 0 0 0 or 1 0 or 1 100, 101, 102 or 103 1 1 0 0 1 0 or 1 0
or 1 104, 105, 106 or 107 1 1 0 1 0 0 or 1 0 or 1 108, 109, 110 or
111 1 1 0 1 1 0 or 1 0 or 1 112, 113, 114 or 115 1 1 1 0 0 0 or 1 0
or 1 116, 117, 118 or 119 1 1 1 0 1 0 or 1 0 or 1 120, 121, 122 or
123 1 1 1 1 0 0 or 1 0 or 1 124, 125, 126 or 127 1 1 1 1 1 0 or 1 0
or 1
[0059] By utilizing the above tables the binary representation of
the number of correctly decoded transport blocks is adapted to a 5
bit long indication parameter by truncating the LSB(s) and thus,
the original resolution of said number is halved/quartered during
the adaptation.
[0060] As a simple alternative to the above truncation or other
adaptation techniques applied to the number of correctly decoded
transport blocks in order to fit the number into a parameter with
limited length (like 5 bits), it's always possible to count said
number for a single transport channel only. Selection of such
transport channel can be, for example, [0058] signalled by the
network to the terminal at call set-up, or automatic, e.g. the
first one utilizing a CRC is selected.
[0061] When only one transport channel is counted, the maximum
number of correctly decoded (transport) blocks during a SACCH
reporting period remains at 24.
[0062] As another supplementary or fully independent adoption
method a non-linear reporting scale is presented. The scale would
be made in a way that the reporting resolution is higher for some
numbers, for example: [0061] for the range where all blocks are
sent and a low number of blocks are incorrect (i.e. for typical
conditions); [0062] and eventually for the range where only a few
correct blocks are correctly decoded (i.e for the DTX
(discontinuous transmission) case where only a few blocks per
reporting period have been sent).
[0063] An example of aforesaid scale is given in Table 4.
TABLE-US-00004 TABLE 4 Non-linear mapping NBR_RCVD_BLOCKS Received
Blocks bit 5 bit 4 bit 3 bit 2 bit 1 0 0 0 0 0 0 1 0 0 0 0 1 2 0 0
0 1 0 3, 4 0 0 0 1 1 5, 6 0 0 1 0 0 7, 8 0 0 1 0 1 9, 10 0 0 1 1 0
11, 12 0 0 1 1 1 13, 14 0 1 0 0 0 15, 16 0 1 0 0 1 17, 18 0 1 0 1 0
19 0 1 0 1 1 20 0 1 1 0 0 21 0 1 1 0 1 22 0 1 1 1 0 23 0 1 1 1 1 24
1 0 0 0 0 25, 26 1 0 0 0 1 27, 28 1 0 0 1 0 29, 30 1 0 0 1 1 31, 32
1 0 1 0 0 33, 34 1 0 1 0 1 35, 36 1 0 1 1 0 37, 38 1 0 1 1 1 39, 40
1 1 0 0 0 41, 42 1 1 0 0 1 43 1 1 0 1 0 44 1 1 0 1 1 45 1 1 1 0 0
46 1 1 1 0 1 47 1 1 1 1 0 48 1 1 1 1 1
[0064] Naturally, the described basic principles of the invention
are not limited to any certain transmission direction or device.
They may be used in both uplink and downlink directions and in e.g.
a mobile terminal and a network element (e.g. a base station (BS),
a base station controller (BSC), or a combination thereof).
[0065] FIG. 5 discloses a flow diagram of the method of the
invention. At method start-up 502 a device, referring to a network
entity (e.g. a BS, BSC, or a combination thereof) or to a wireless
communications device like a mobile terminal may, for example, load
the software performing the method of the invention to the memory
and start execution. In addition, necessary memory areas can be
initialised and communication connections established. In step 504
information about the maximum number of correctly decoded transport
blocks is obtained. Such step may additionally or alternatively be
executed after step 507 described later, this option depicted by
dotted arrow in the figure, for example, which is advantageous
especially if the TFCS is actually changed during the reporting
period and therefore the maximum number of correctly decoded blocks
is not known for sure until the reporting period has expired and
the indication is about to be sent. Whenever several TFCSs are used
during the reporting period, a number of different procedures can
be performed for determining a proper NbTBmax. E.g. the NbTBmax can
be defined as the maximum value of NbTBmax values of different
TFCSs used during the reporting period, or NbTBmax can be
constructed as the sum of the different NbTBmax values used.
Reverting back to step 504 internals, the terminal may receive
related basic data at call-set up, for example, when the TFCS and
TFCs are determined and signalled, and then analyse the data as
described hereinbefore with possible additional/special conditions
in order to determine the required number. The information may also
be obtained through a number of (partial) TFCS reconfigurations
including deletion/addition/modifications of certain TFC(s)/TFs.
The information may also be transmitted as such between the ends of
a connection in question. The network element providing the
information to the terminal may create it by itself or receive it
from another network element.
[0066] In step 506 (and 507 in which it is checked if the current
reporting period has elapsed) the terminal receives transport
block(s) included in radio packet(s). The terminal determines the
number of correctly decoded blocks in step 508 by utilizing the
rules set forth hereinbefore. In step 510 the terminal adapts an
indication of the determined number to be sent 512 (e.g. as a data
field/parameter in a message) to the network. Adaptation can mean
e.g. truncating a binary representation of said number if needed,
selecting a proper element from a non-linear mapping table (see
Table 4 for an example) etc. In step 514 the network element
processing and/or analysing the number of correctly decoded blocks
receives the indication thereof and decodes 516 it on the basis of
the TFC/TFCS configuration in force during the reporting period
about which the indication concerns. The network may utilize the
decoded information to adapt some connection parameters (channel
coding etc) to better match the prevailing and possibly altered
communication environment. The method is ended in step 518.
[0067] FIG. 6 depicts one option for basic components of a device
like a network element (or a combination of separate elements) or a
mobile terminal capable of processing and transferring data in
accordance with the invention. Wording "mobile terminal" refers to,
in addition to contemporary cellular phones, also to more
sophisticated multimedia terminals, hand held and laptop computers
etc capable of wireless communication. Memory 604, divided between
one or more physical memory chips, comprises necessary code 616,
e.g. in a form of a computer program/application, and configuration
(TFCS/TFC/reporting period/additional rules & definitions for
determination of maximum number/current number of transport blocks)
data 612. Processing unit 602 is required for the actual execution
of the method in accordance with instructions 616 stored in memory
604. Display 606 and keypad 610 are optional components often found
useful for providing necessary device control and data
visualization means (user interface) to the user of the device.
Data transfer means 608, e.g. a fixed data transmission interface
or a radio transceiver or both, are required for handling data
exchange, for example, receipt of configuration data from other
devices and/or transmission of configuration data to other devices.
Code 616 for the execution of the proposed method can be stored and
delivered on a carrier medium like a floppy, a CD or a memory
card.
[0068] The scope of the invention can be found in the following
claims. It should be noted that utilized devices, method steps,
adaptation techniques etc may vary depending on the scenario, still
converging to the basic idea of this invention. For example,
truncation of bits can be done differently to the presented
examples, as well as the non-linear mapping. It's obvious that the
parameter lengths may also differ from the ones presented
hereinbefore.
REFERENCES
[0069] [1] 3GPP TR 45.902 V.6.2.0 Technical Specification Group
GSM/EDGE, Radio Access Network; Flexible Layer One (Rel 6) [0070]
[2] 3GPP TS 45.002 V6.3.0 Technical Specification Group GSM/EDGE,
Radio Access Network; Multiplexing and multiple access on the radio
path (Rel 6) [0071] [3] 3GPP TS 44.160 Technical Specification
Group GSM/EDGE, General Packet Radio Service (GPRS); Mobile Station
(MS)--Base Station System (BSS) interface; Radio Link
Control/Medium Access Control (RLC/MAC) protocol Iu mode (Rel 6)
[0072] [4] 3GPP TS 44.118 Technical Specification Group GSM/EDGE,
Radio Access Network; Mobile radio interface layer 3 specification;
Radio Resource Control (RRC) protocol Iu Mode (Rel 5) [0073] [5]
3GPP TS 45.008 Technical Specification Group GSM/EDGE Radio Access
Network; Radio subsystem link control (Rel 6) [0074] [6] 3GPP TS
44.018 Technical Specification Group GSM/EDGE Radio Access Network;
Mobile radio interface layer 3 specification; Radio Resource
Control (RRC) protocol (Rel 6).
* * * * *