U.S. patent application number 17/530571 was filed with the patent office on 2022-03-10 for methods and arrangements in a wireless communications system.
The applicant listed for this patent is Optis Wireless Technology, LLC. Invention is credited to Johan BERGMAN, Dirk GERSTENBERGER.
Application Number | 20220078786 17/530571 |
Document ID | / |
Family ID | 1000005986764 |
Filed Date | 2022-03-10 |
United States Patent
Application |
20220078786 |
Kind Code |
A1 |
GERSTENBERGER; Dirk ; et
al. |
March 10, 2022 |
METHODS AND ARRANGEMENTS IN A WIRELESS COMMUNICATIONS SYSTEM
Abstract
The present invention relates to methods and arrangements that
make it possible to control the delay for the UEs to access the EUL
resources in the Enhanced Uplink in CELL_FACH state procedure,
independently from the delay for the UEs to access ordinary UL
resources in the RACH procedure. This is achieved by a solution
where the timing of entering (or re-entering) a transmission
procedure for Enhanced Uplink in CELL_FACH state is controlled with
the help of a transmission control parameter defined specifically
for this transmission procedure, instead of using the same
parameter as for the RACH procedure.
Inventors: |
GERSTENBERGER; Dirk;
(Stockholm, SE) ; BERGMAN; Johan; (Stockholm,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Optis Wireless Technology, LLC |
Plano |
TX |
US |
|
|
Family ID: |
1000005986764 |
Appl. No.: |
17/530571 |
Filed: |
November 19, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16516397 |
Jul 19, 2019 |
11184884 |
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17530571 |
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|
15406991 |
Jan 16, 2017 |
10390334 |
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16516397 |
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14257479 |
Apr 21, 2014 |
9585128 |
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15406991 |
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12865867 |
Aug 3, 2010 |
8705434 |
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PCT/SE2008/024170 |
Dec 16, 2008 |
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14257479 |
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61025900 |
Feb 4, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 72/0413 20130101;
H04W 74/08 20130101; H04W 74/006 20130101; H04W 56/003 20130101;
H04W 74/0833 20130101; H04W 48/08 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04; H04W 56/00 20060101 H04W056/00; H04W 74/08 20060101
H04W074/08 |
Claims
1. A user equipment of a wireless communication network capable of
entering a transmission procedure, wherein the type of transmission
procedure is a random access procedure, the user equipment
comprising: a receiver operative to receive at least a first set of
transmission control parameters associated with a timing for
entering an enhanced uplink procedure when the user equipment is in
CELL_FACH state, the first set of transmission control parameters
including a first persistence value parameter and chosen to reduce
a delay of access in comparison to an access time for access by the
user equipment to ordinary uplink resources using a standard random
access channel (RACH) procedure when the user equipment is not in
CELL_FACH state; and a microprocessor configured to: derive the
timing for entering the transmission procedure using the first set
of transmission control parameters including the first persistence
value parameter, when initiating an enhanced uplink procedure when
the user equipment is in CELL_FACH state, and enter the enhanced
uplink transmission procedure according to the derived timing.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent
application Ser. No. 16/516,397 filed on Jul. 19, 2019, which is a
Continuation of U.S. patent application Ser. No. 15/406,991 filed
on Jan. 16, 2017 (issued as U.S. Pat. No. 10,390,334), which is a
Continuation of U.S. patent application Ser. No. 14/257,479 filed
on Apr. 21, 2014 (issued as U.S. Pat. No. 9,585,128), which is a
Continuation of U.S. patent application Ser. No. 12/865,867 filed
on Aug. 3, 2010 (issued as U.S. Pat. No. 8,705,434), which claims
priority from International Patent Application No.
PCT/SE2008/024170, filed Dec. 16, 2008, which claims priority from
U.S. Provisional Patent Application No. 61/025,900 filed Feb. 4,
2008, which are all incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates to methods and arrangements in
a wireless communications system, in particular to methods and
arrangements for controlling the timing of a user equipment
entering an uplink transmission procedure.
BACKGROUND
[0003] The Universal Mobile Telecommunication System (UMTS), also
referred to as the third generation (3G) system or the wideband
code division multiplexing access (WCDMA) system, is designed to
succeed GSM. UMTS Terrestrial Radio Access Network (UTRAN) is the
radio access network of a UMTS system.
[0004] High-Speed Downlink Packet Access (HSPDA) is an evolution of
UTRAN bringing further enhancements to the provisioning of
packet-data services both in terms of system and end-user
performance. The downlink packet-data enhancements of HSDPA are
complemented with Enhanced Uplink (EUL), also known as High-Speed
Uplink Packet Access (HSUPA). EUL provides improvements in the
uplink capabilities and performance in terms of higher data rates,
reduced latency, and improved system capacity, and is therefore a
natural complement to HSDPA. HSDPA and EUL are often jointly
referred to as High-Speed Packet Access (HSPA).
[0005] FIG. 1 illustrates a wireless communications system, such as
a HSPA system, including a radio access network such as the UTRAN.
The UTRAN architecture comprises at least one radio base station
(NodeB) 130, connected to one or more Radio Network Controllers
(RNC) 100. The UTRAN is connected over an interface to a Core
Network (CN) 120. The UTRAN and the CN 120 provide communication
and control for a plurality of user equipments (UE) 150. The UEs
150 are wirelessly connected to at least one NodeB 130, and they
communicate with each other over downlink and uplink channels.
[0006] In a UTRAN, the dedicated transport channel is called
Dedicate Channel (DCH). The DCH carries all the information to/from
a specific UE from/to higher layers including the data for the
actual service and higher layer control information. In a UTRAN
with HSPA, the HSPA enhancements are implemented through new
dedicated transport channels: the High-Speed Downlink Shared
Channel (HS-DSCH) for HSDPA and the Enhanced Dedicated Channel
(E-DCH) for EUL.
[0007] Packet-data is often transmitted in bursts, which gives
occasional periods of transmission activity and no transmission
activity in between these periods. From a user performance
perspective, it is advantageous to keep the HS-DSCH and E-DCH
configured to rapidly be able to transmit any user data. At the
same time, maintaining the connection in uplink and downlink comes
at a cost. From a network perspective, there is a cost in uplink
interference from the control data transmission even in absence of
data transmission. From a UE perspective, power consumption is the
main concern; even when no data is received the UE needs to
transmit and monitor control data. To reduce UE power consumption,
UMTS/WCDMA has several connected mode states which define what kind
of physical channels a UE is using: Cell_DCH 220, Cell_FACH 210,
and Cell_PCH/URA_PCH 200, schematically illustrated in FIG. 2, with
arrows defining the possible state changes.
[0008] The lowest power consumption is achieved when the UE is in
one of the two paging states Cell_PCH/URA_PCH 200. For exchange of
data, the UE needs to be moved to the Cell_FACH 210 or Cell_DCH 220
state. The high transmission activity state is known as CELL_DCH
220. In this state, a dedicated physical channel is allocated to
the UE and the UE can use e.g. HS-DSCH and E-DCH for exchanging
data with the network. This state allows for rapid transmission of
large amounts of user data, but also has the highest UE power
consumption. In order to avoid a waste of UE battery, the UE is
switched to CELL_FACH 210 state if there hasn't been any
transmission activity for a certain period of time. In Cell_FACH
210 state, the UE can transmit small amounts of packet data as part
of the random access procedure on the Random Access Channel (RACH).
The UE also monitors common downlink channels (Forward Access
Channel (FACH)) for small amounts of user data and Radio Resource
Control (RRC) signalling from the network.
[0009] The RACH is an uplink transport channel intended to be used
to carry control information from the UE, such as requests to set
up a connection. RACH is mapped on the Physical Random Access
Channel (PRACH). As stated above, the RACH procedure can also be
used to send small amounts of packet data from the UE to the
network in the Cell_FACH state.
[0010] The following paragraphs outlines the Layer 2 (L2) Medium
Access Control (MAC) description for controlling the transmissions
in the RACH procedure, as described in the 3GPP (3.sup.rd
Generation Partnership Project) technical specification TS 25.321.
The RACH transmissions are controlled by the UE MAC sublayer,
hereinafter referred to as UE (MAC). The UE (MAC) receives the
following RACH transmission control parameters from the Radio
Resource Control (RRC): [0011] a set of Access Service Class (ASC)
parameters, which includes for each ASC, i=0, . . . , NumASC an
identification of a PRACH partition and a persistence value Pi
(transmission probability); [0012] maximum number of preamble
ramping cycles Mmax; [0013] range of back-off interval for timer
TBO1, given in terms of numbers of transmission time (10 ms)
intervals NBO1 max and NBO1 min.
[0014] When there is data to be transmitted, the UE (MAC) selects
the ASC from the available set of ASCs, which consists of an
identifier i of a certain PRACH partition and an associated
persistence value Pi. Based on the persistence value Pi (used in a
persistency test), the UE decides whether to enter the Layer 1 (L1)
PRACH transmission procedure in the present transmission time
interval (TTI) or not. If transmission is not allowed, a new
persistency test is performed in the next TTI, and the persistency
test is repeated until transmission is allowed. When transmission
is allowed, the PRACH transmission procedure--starting with a
preamble power ramping cycle--is entered. The UE (MAC) then waits
for access information from L1.
[0015] When the preamble has been acknowledged on the Acquisition
Indicator Channel (AICH), L1 access information with parameter
value "ready for data transmission" is indicated to the UE (MAC).
The data transmission is then requested, and the PRACH transmission
procedure is completed with transmission of the PRACH message part
according to L1 specifications. When no acknowledgement on AICH is
received while the maximum number of preamble retransmissions is
reached, a new persistency test is performed in the next TTI. The
timer T2 ensures that two successive persistency tests are
separated by at least one 10 ms time interval.
[0016] If a negative acknowledgement is received on AICH, a
back-off timer TBO1 is started. After expiry of the timer, a
persistency test is performed again. Back-off timer TBO1 is set to
an integer number NBO1 of 10 ms time intervals, randomly drawn
within an interval 0.ltoreq.NBO1min.ltoreq.NBO1.ltoreq.NBO1max
(with uniform distribution). NBO1 min and NBO1 max may be set equal
when a fixed delay is desired, and even to zero when no delay other
than the one due to the persistency test is desired.
[0017] Before a persistency test is performed it shall be checked
whether any new RACH transmission control parameters have been
received from RRC, and the latest set of RACH transmission control
parameters shall be applied. If the maximum number of preamble
ramping cycles Mmax is exceeded, failure of RACH transmission shall
be reported to higher layer.
[0018] The RACH procedure has to cope with the near-far problem, as
there is no exact knowledge of the required transmission power when
entering the transmission procedure. As indicated above, this is
solved with a preamble transmission procedure with power ramping.
In the following, a summary of the different UE steps of a RACH
procedure will be described with reference to FIG. 3a.
[0019] The UE decodes the broadcast channel 301 to find out the
available RACH sub-channels and their scrambling codes and
signatures, as well as the transmission control parameters (see
above). Based on the persistence value Pi, the UE decides whether
to enter the transmission procedure in the present TTI or not. This
so called persistency test 302 is explained with more details
below. If the persistency test allows transmission 303/YES, the UE
selects randomly one of the RACH sub-channels. If the persistency
test does not allow transmission 303/NO, the UE needs to wait for
the next TTI before a new persistency test 302 is performed. This
is repeated until transmission is allowed.
[0020] The downlink power level is measured and the initial RACH
power level is set 304 based on this measurement (according to the
open loop power control). A first preamble is transmitted 305. The
UE decodes the Acquisition Indicator Channel (AICH) 306 to see
whether the NodeB has detected the preamble. In case no AICH is
detected 306/NO, the UE increases the preamble transmission power
304 by a step given by the NodeB. The preamble is retransmitted 305
in the next available access slot. If the maximum number of
preambles has been reached, a new persistency test 302 is
performed.
[0021] When an acknowledgement (ACK) from the NodeB is detected on
AICH 306/ACK, the UE transmits the message part of the RACH
transmission 307. In the case of a blocking situation (e.g. two UEs
requesting a connection at the same time) the NodeB will transmit a
NACK on the AICH 306/NACK to one of the UEs. This will force the UE
to exit the RACH procedure and re-enter it after a certain delay
controlled by the timer TBO1 308. After expiry of the timer, a new
persistency test 302 is performed to check if the UE is allowed to
re-enter the procedure.
[0022] During the persistency test 302, referred to above, the UE
generates a random value between 0 and 1 and checks whether this
value is within the interval given by the persistency value Pi. A
UE generating a random value below a threshold defined by the
persistency value Pi, will be allowed to start the RACH procedure.
By configuring the persistency value parameter, the probability of
a UE entering the preamble transmission procedure can be
controlled. As an example, if the persistency value is set to 0.9,
there is a 90% probability that the UE will initiate the RACH
procedure, which means that the delay is typically rather short,
while with a persistency value of 0.1, there is only a 10% chance
of the UE initiating the procedure, thus typically giving a longer
delay.
[0023] The network steps in the RACH procedure are described below
with reference to FIG. 3b. The RNC configures the transmission
control parameters and transmits them via layer3 signalling. The
NodeB broadcasts the available RACH sub-channels and their
scrambling codes and signatures, as well as the transmission
control parameters 311. When the UE has reached the needed preamble
transmission power level, the NodeB will receive the preamble 312.
NodeB will then check for available resources 313, and will
transmit an ACK and the resource allocation 314 when resources are
available 313/YES. After having received the message part of the
RACH transmission 315, the resources will be released by the NodeB
316. If the resource availability check is negative 313/NO, a NACK
will be transmitted on the AICH instead.
[0024] In the 3GPP, the transmission procedure in the Enhanced
Uplink in CELL_FACH state has been discussed, and it has been
agreed to use a preamble transmission procedure with power ramping
with the same transmission control parameters as in the ordinary
RACH procedure (as described above), and to use a specific AICH or
EUL AICH (E-AICH) sequences indicating EUL resources to the UE.
This procedure will hereinafter be referred to as Enhanced Uplink
in CELL_FACH state procedure.
[0025] A disadvantage of this solution, is that the delay for the
UEs to access the EUL resources in the Enhanced Uplink in CELL_FACH
state procedure, is the same as the delay for the UEs to access
ordinary UL resources in the RACH procedure. Since both procedures
serve quite different purposes, an equal delay will give
sub-optimal performance of the Enhanced Uplink in CELL_FACH state
procedure. Solutions for a reduced delay for the Enhanced Uplink in
CELL_FACH state procedure has been discussed in 3GPP, and it has
been proposed to re-enter the preamble transmission with the power
level of the latest preamble transmission before NACK,
alternatively with the power level minus a small power back-off of
the latest preamble transmission before NACK.
SUMMARY
[0026] The object of the present invention is to provide methods
and arrangements that obviate the above described disadvantage and
that make it possible to reduce the delay for the UEs to access the
EUL resources in the Enhanced Uplink in CELL_FACH state
procedure.
[0027] This is achieved by a solution where the timing for entering
(or re-entering) the transmission procedure in Enhanced Uplink in
CELL_FACH state is controlled with the help of a set of
transmission control parameters defined specifically for this
transmission procedure. The UE thus selects transmission control
parameters dependent on the type of transmission procedure, when
entering the transmission procedure.
[0028] Thus in accordance with a first aspect of the present
invention, a method in a radio network controller of a wireless
communication network, for supporting a UE entering a transmission
procedure is provided. The radio network controller communicates
with at least one UE via layer 3 signalling. The type of
transmission procedure is a RACH procedure or an enhanced uplink in
CELL_FACH state procedure. In the method a first set of
transmission control parameters are configured, which are
associated with timing for a UE entering a RACH procedure.
Furthermore a second set of transmission control parameters are
configured, which are associated with timing for a UE entering an
enhanced uplink in CELL_FACH state procedure. The timing for
entering the transmission procedure for the UE is controlled
depending on the type of transmission procedure, by transmitting at
least the second set of transmission control parameters to the at
least one UE.
[0029] In accordance with a second aspect of the present invention,
a method in a UE of a wireless communication network, for entering
a transmission procedure is provided. The type of transmission
procedure is a RACH procedure or an enhanced uplink in CELL_FACH
state procedure. In the method at least a second set of
transmission control parameters are received via layer 3
signalling, where this second set of parameters is associated with
timing for entering an enhanced uplink in CELL_FACH state
procedure. Furthermore, the timing for entering the transmission
procedure using the second set of transmission control parameters
is derived, when initiating an enhanced uplink in CELL_FACH state
procedure, and the timing for entering the transmission procedure
using a first set of transmission control parameters associated
with timing for entering a RACH procedure is derived, when
initiating a RACH procedure. In the method the transmission
procedure is entered, depending on the type of transmission
procedure, according to the derived timing.
[0030] In accordance with a third aspect of the present invention a
radio network controller of a wireless communication network is
provided. The radio network controller is configured to communicate
with at least one UE via layer 3 signalling and is capable to
support the UE entering a transmission procedure. The type of
transmission procedure is a RACH procedure or an enhanced uplink in
CELL_FACH state procedure. The radio network controller comprises
means for configuring a first set of transmission control
parameters associated with timing for a UE entering a RACH
procedure. Furthermore, it comprises means for configuring a second
set of transmission control parameters associated with timing for a
UE entering an enhanced uplink in CELL_FACH state procedure. It
also comprises a controlling unit for controlling the timing for
entering the transmission procedure for the at least one UE
depending on the type of transmission procedure. The controlling
unit is further configured to transmit at least the second set of
transmission control parameters to the at least one UE for
controlling the timing.
[0031] In accordance with a fourth aspect of the present invention,
a UE of a wireless communication network is provided, capable of
entering a transmission procedure. The type of transmission
procedure is a RACH procedure or an enhanced uplink in CELL_FACH
state procedure. The UE is characterised by means for receiving at
least a second set of transmission control parameters via layer 3
signalling, where this second set of parameters is associated with
timing for entering an enhanced uplink in CELL_FACH state
procedure, and means for deriving the timing for entering the
transmission procedure using the second set of transmission control
parameters, when initiating an enhanced uplink in CELL_FACH state
procedure. The UE further comprises means for deriving the timing
for entering the transmission procedure using a first set of
transmission control parameters associated with timing for entering
a RACH procedure, when initiating a RACH procedure. It also
comprises means for entering the transmission procedure, depending
on the type of transmission procedure, according to the derived
timing.
[0032] An advantage of embodiments of the present invention is that
the time delay before entering the transmission procedure for
Enhanced Uplink in CELL_FACH state, and the time delay between
exiting the procedure (when receiving a NACK) and re-entering it,
can be reduced compared to the corresponding delays for the RACH
procedure. Thus, the time it takes to access EUL resources in the
transmission procedure may always be optimized for the Enhanced
Uplink in CELL_FACH state purpose, regardless of what is needed for
the RACH procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 illustrates schematically a part of a UTRAN wherein
the present invention may be implemented.
[0034] FIG. 2 illustrates schematically the different connected
mode states of a UE in UMTS/WCDMA.
[0035] FIGS. 3a and 3b are flowcharts of the UE steps and the
network steps in a RACH procedure respectively, according to prior
art.
[0036] FIGS. 4a and 4b are flowcharts of the methods of the RNC and
UE respectively according to embodiments of the present
invention.
[0037] FIG. 5 illustrates schematically the RNC and UE according to
embodiments of the present invention.
DETAILED DESCRIPTION
[0038] In the following, the invention will be described in more
detail with reference to certain embodiments and to accompanying
drawings. For purposes of explanation and not limitation, specific
details are set forth, such as particular scenarios, techniques,
etc., in order to provide a thorough understanding of the present
invention. However, it will be apparent to one skilled in the art
that the present invention may be practised in other embodiments
that depart from these specific details.
[0039] Moreover, those skilled in the art will appreciate that the
functions and means explained herein below may be implemented using
software functioning in conjunction with a programmed
microprocessor or general purpose computer, and/or using an
application specific integrated circuit (ASIC). It will also be
appreciated that while the current invention is primarily described
in the form of methods and devices, the invention may also be
embodied in a computer program product as well as in a system
comprising a computer processor and a memory coupled to the
processor, wherein the memory is encoded with one or more programs
that may perform the functions disclosed herein.
[0040] The present invention is described herein by way of
reference to particular example scenarios. In particular the
invention is described in a non-limiting general context in
relation to a HSPA wireless communications system. It should though
be noted that the invention and its exemplary embodiments may also
be applied to other types of wireless communications system with
similar characteristics to HSPA, in terms of transmission
procedures.
[0041] As mentioned above, it has been discussed how to reduce the
delay for the UEs to access the EUL resources again after a NACK in
the Enhanced Uplink in CELL_FACH state procedure. It has for
example been proposed to re-enter the preamble transmission with
the power level of the latest preamble transmission before NACK,
alternatively with the power level minus a small power back-off of
the latest preamble transmission before NACK. However, the actual
total delay for a UE, counting from exiting the Enhanced Uplink in
CELL_FACH state procedure to the point where a preamble is
successfully received at the NodeB, includes not only the time for
sending preambles during the power ramping phase. It also includes
the time consumed before the preamble transmission procedure is
actually entered and the first preamble is transmitted.
[0042] The timing of the first preamble transmission--both when
entering and re-entering the procedure--is controlled by different
transmission control parameters. These parameters are configured by
the RNC and informed to the UE through the NodeB via Layer3
signalling. One such parameter is the persistence value parameter
which is used in the persistency test, thus affecting the timing of
entering and re-entering the procedure, as described above for the
RACH procedure. Another parameter is the back-off time parameter
which defines the range of the back-off interval. This range is
used when determining what the back-off timer TBO1 is set to, as
described above. The timer TBO1 affects the timing of re-entering
the procedure after a NACK.
[0043] The basic idea with the present invention is to use
specifically defined values for the above mentioned transmission
control parameters for the Enhanced Uplink in CELL_FACH state
procedure, in order to reduce the delay for the UEs to access the
EUL resources in this procedure. The transmission control
parameters used for the RACH procedure are not adapted for the
Enhanced Uplink in CELL_FACH state procedure, so separate
parameters are needed to optimize the Enhanced Uplink in CELL_FACH
state procedure for its purpose. In embodiments of the present
invention, the RNC thus configures separate Enhanced Uplink in
CELL_FACH state procedure parameters. The parameters are
broadcasted to all UEs, or transmitted to dedicated UEs.
[0044] According to an example of the present invention, the RNC
configures a first set of (i.e. one or more) transmission control
parameters to be used for the RACH procedures, but also a separate
second set of (i.e. one or more) transmission control parameters to
be used for Enhanced Uplink in CELL_FACH state procedure, in order
to control the timing of entering and re-entering the RACH
procedure and the Enhanced Uplink in CELL_FACH state procedure
separately. Either only the second set of parameters, or both the
first and the second set of parameters, are signaled with Radio
Resource Control (RRC) signalling transparently via the NodeB to
the UE. As mentioned above, the parameters may be broadcasted to
all UEs.
[0045] In a first embodiment of the present invention, the second
set of transmission control parameters comprises the persistence
value parameter only. In this embodiment there will thus be a
separate persistence value P.sub.i,ENHANCED UPLINK IN CELL FACH
STATE to be used for controlling the timing of entering or
re-entering the Enhanced Uplink in CELL_FACH state procedure. By
setting a higher persistence value, the UE will faster enter or
re-enter the Enhanced Uplink in CELL_FACH state procedure, as the
probability for the UEs to randomly generate a value below the
persistency value is increased (as explained above).
[0046] In a second embodiment, the second set of transmission
control parameters comprises the back-off time parameter only. In
this embodiment there will thus be a separate back-off time
parameter, comprising a minimum and a maximum value (NBO1 min and
NBO1 max) defining the range of the NBO1 interval, used when
setting the back-off timer TBO1 for the Enhanced Uplink in
CELL_FACH state procedure (as described above). By setting the NBO1
min and NBO1 max values to zero e.g., the UE will faster perform a
new persistency test when re-entering the procedure, as the timer
TBO1 will always be set to zero.
[0047] In a third embodiment, the second set of transmission
control parameters comprises both the persistence value parameter
and the back-off time parameter. This is thus a combination of the
first and the second embodiment described above, making it possible
to control the timing of entering the procedure both by e.g. using
a higher persistency value and by using an adapted back-off time
parameter.
[0048] FIG. 4a is a flowchart of the method for the RNC, according
to an embodiment of the present invention. In step 410, the RNC
configures a first set of transmission control parameters
associated with timing for a UE entering a RACH procedure. This
first set of parameters could comprise the persistence value
parameter or the back-off time parameter or both. Furthermore, the
RNC configures 420 a separate second set of transmission control
parameters associated with timing for a UE entering an enhanced
uplink in CELL_FACH state procedure. This second set of parameters
could also comprise the persistence value parameter or the back-off
time parameter or both (see description of first, second and third
embodiment above), and it does not need to comprise the same set of
parameters as in the first set. The RNC then controls 430 the
timing for entering the transmission procedure for the UE depending
on the type of transmission procedure, by transmitting at least the
second set of transmission control parameters to the UE. The timing
of the transmission in the Enhanced Uplink in CELL_FACH state
procedure is controlled based on the parameters of the second set,
independently of the timing of the transmission in the RACH
procedure.
[0049] Furthermore, FIG. 4b is a flowchart of the method for the
UE, according to an embodiment of the present invention. In step
440, the UE receives at least a second set of transmission control
parameters associated with timing for entering an enhanced uplink
in CELL_FACH state procedure, via layer3 signalling (RRC) from the
RNC. When initiating an enhanced uplink in CELL_FACH state
procedure, the UE will derive 450 the timing for entering the
transmission procedure using this second set of transmission
control parameters. If this second set comprises a persistence
value parameter, then the UE will use this parameter in the
persistency test that precedes the preamble transmission procedure
to find out when to enter the transmission procedure (delay due to
the persistency test, corresponding to the step 302, 303 in FIG.
3a). If the second set also comprises a back-off time parameter,
then the UE will use this parameter for setting the TBO1 timer and
thus to find out when to re-enter the enhanced uplink in CELL_FACH
state procedure (delay due to TBO1 timer expiry and persistency
test corresponding to step 308 and 302, 303 in FIG. 3a). When
initiating a RACH procedure, the UE will derive 460 the timing for
entering the transmission procedure using a first set of
transmission control parameters associated with timing for entering
a RACH procedure instead. Finally, the UE will also actually enter
470 the relevant transmission procedure according to the timing
that has been derived. With e.g. a higher persistency value for the
enhanced uplink in Cell-FACH state procedure than for the RACH
procedure, the UE will thus typically faster access the enhanced
uplink resources than the ordinary dedicated channel resources.
[0050] Schematically illustrated in FIG. 5 and according to the
embodiments of the present invention, the RNC 100 comprises means
for configuring 101 a first set of transmission control parameters
associated with timing for a UE entering a RACH procedure, and
means for configuring 101 a second set of transmission control
parameters associated with timing for a UE entering an enhanced
uplink in CELL_FACH state procedure. It also comprises a
controlling unit 102 for controlling the timing for entering the
transmission procedure for the UE depending on the type of
transmission procedure. The controlling unit 102 is further
configured to transmit at least the second set of transmission
control parameters to the UE for controlling the timing.
[0051] Also illustrated in FIG. 5 is the UE 150. It comprises a
receiver 151 for receiving at least a second set of transmission
control parameters associated with timing for entering an enhanced
uplink in CELL_FACH state procedure via layer 3 signalling. It also
comprises means for deriving 152 the timing for entering the
transmission procedure using the second set of transmission control
parameters. This is done when initiating an enhanced uplink in
CELL_FACH state procedure. The UE further comprises means for
deriving 152 the timing for entering the transmission procedure
using a first set of transmission control parameters associated
with timing for entering a RACH procedure. This is done when
initiating a RACH procedure. Finally, the UE comprises means for
entering 153 the transmission procedure depending on the type of
transmission procedure according to the derived timing.
[0052] It should be noted that the means illustrated in FIG. 5 may
be implemented by physical or logical entities using software
functioning in conjunction with a programmed microprocessor or
general purpose computer, and/or using an application specific
integrated circuit (ASIC).
[0053] The above mentioned and described embodiments are only given
as examples and should not be limiting to the present invention.
Other solutions, uses, objectives, and functions within the scope
of the invention as claimed in the accompanying patent claims
should be apparent for the person skilled in the art.
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