U.S. patent application number 12/091510 was filed with the patent office on 2009-06-18 for method and apparatus of transmission of an access probe in a wireless communication systems.
This patent application is currently assigned to QUALCOMM INCORPORATED. Invention is credited to Rajat Prakash.
Application Number | 20090156207 12/091510 |
Document ID | / |
Family ID | 37687691 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090156207 |
Kind Code |
A1 |
Prakash; Rajat |
June 18, 2009 |
METHOD AND APPARATUS OF TRANSMISSION OF AN ACCESS PROBE IN A
WIRELESS COMMUNICATION SYSTEMS
Abstract
A method and apparatus for transmission of an access probe in a
wireless communication system is provided. The method includes
determining a ProbeSequenceNumber, determining an AccessSequenceID
and adding it to a public data, determining ProbeNumber greater
than MaxProbesPerSequence to perform the following: setting the
ProbeNumber to `1`, incrementing the ProbeSequence Number by 1,
determining an AccessCarrier by monitoring LoadControl bits on
different carriers, using overhead parameters corresponding to
selected Access Carrier, adding the AccessCarrier to the public
data. The method further includes determining a DelayToNextProbe
value, starting a timer for the DelayToNextProbe frames,
determining an InitialProbePower value, transmitting a probe using
AccessSequenceID, PilotPN, AccessCarrier and Power and incrementing
the ProbeNumber.
Inventors: |
Prakash; Rajat; (La Jolla,
CA) |
Correspondence
Address: |
Amin, Turocy & Calvin LLP
127 Public Square, 57th Floor, Key Tower
Cleveland
OH
44114
US
|
Assignee: |
QUALCOMM INCORPORATED
San Diego
CA
|
Family ID: |
37687691 |
Appl. No.: |
12/091510 |
Filed: |
October 27, 2006 |
PCT Filed: |
October 27, 2006 |
PCT NO: |
PCT/US06/42488 |
371 Date: |
October 1, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60731037 |
Oct 27, 2005 |
|
|
|
Current U.S.
Class: |
455/434 |
Current CPC
Class: |
H04W 52/325 20130101;
H04B 7/216 20130101; Y02D 30/00 20180101; H04W 72/085 20130101;
H04L 5/0057 20130101; H04W 72/0473 20130101; H04W 52/58 20130101;
H04W 24/02 20130101; H04B 7/2628 20130101; H04W 52/146 20130101;
H04L 27/2601 20130101; H04J 13/00 20130101; H04W 52/16 20130101;
H04W 52/48 20130101 |
Class at
Publication: |
455/434 |
International
Class: |
H04W 4/00 20090101
H04W004/00 |
Claims
1. A method of transmission of an access probe in a wireless
communication system, characterized in that: determining a
ProbeSequenceNumber; determining an AccessSequenceID and adding the
AccessSequenceID to public data; when ProbeNumber is greater than
MaxProbesPerSequence, performing the following: setting the
ProbeNumber to `1`; incrementing the ProbeSequence Number by 1;
determining an AccessCarrier by monitoring LoadControl bits on
different carriers; using overhead parameters corresponding to a
selected Access Carrier; and adding the AccessCarrier to the public
data; determining a DelayToNextProbe value; starting a timer for
the DelayToNextProbe frames; determining an InitialProbePower
value; transmitting a probe using AccessSequenceID, PilotPN,
AccessCarrier and Power; and incrementing the ProbeNumber.
2. The method as claimed in claim 1, characterized in that
determining the DelayToNextProbe value by determining probe
sequence backoff time if the ProbeNumber is 1; or setting
DelayToNextProbe value to an AccessCycleDuration.
3. The method as claimed in claim 1, characterized in that
decrementing the timer if ReverseLinkSilenceDuration and
ReverseLinkSilencePeriod for a current sector is not active in a
frame; and a superframe containing that frame has the LoadControl
bits transmitted on Control Channel MAC set to a value less than or
equal to a TerminalAccessClass configuration attribute.
4. The method as claimed in claim 1, characterized in that
determining the probe power as a function of InitialAccessPower,
ProbeRampUpStepSize and ProbeNumber.
5. A computer-readable medium including instructions stored
thereon, characterized in that: a first set of instructions for
determining a ProbeSequenceNumber; a second set of instructions for
determining an AccessSequenceID and adding it to public data; a
third set of instructions for, when ProbeNumber is greater than
MaxProbesPerSequence, setting the ProbeNumber to `1`, incrementing
the ProbeSequence Number by 1, determining an AccessCarrier by
monitoring LoadControl bits on different carriers, using overhead
parameters corresponding to selected Access Carrier, and adding the
AccessCarrier to the public data; a fourth set of instructions for
determining a DelayToNextProbe value; a fifth set of instructions
for starting a timer for the DelayToNextProbe frames; a sixth set
of instructions for determining an InitialProbePower value; a
seventh set of instructions for transmitting a probe using
AccessSequinceID, PilotPN, AccessCarrier and Power; and an eighth
set of instructions for incrementing the ProbeNumber.
7. An apparatus operable in a wireless communication system,
characterized in that: means for determining a ProbeSequenceNumber;
means for determining an AccessSequenceID and adding it to a public
data; means for determining ProbeNumber greater than
MaxProbesPerSequence; means for setting the ProbeNumber to `1`;
means for incrementing the ProbeSequence Number by 1; means for
determining an AccessCarrier by monitoring LoadControl bits on
different carriers; means for using overhead parameters
corresponding to selected Access Carrier for the remainder of the
procedures; and means for adding the AccessCarrier to the public
data; means for determining a DelayToNextProbe value; means for
starting a timer for the DelayToNextProbe frames; means for
determining an InitialProbePower value; means for transmitting a
probe using AccessSequinceID, PilotPN, AccessCarrier and Power; and
means for incrementing the ProbeNumber.
8. The apparatus as claimed in claim 7, characterized in that means
for determining the DelayToNextProbe value by determining probe
sequence backoff time if the ProbeNumber is 1; and means for
setting DelayToNextProbe value to an AccessCycleDuration.
9. The apparatus as claimed in claim 7, characterized in that means
for decrementing the timer if ReverseLinkSilenceDuration and
ReverseLinkSilencePeriod for a current sector is not active in a
frame and a superframe containing that frame has the LoadControl
bits transmitted on Control Channel MAC set to a value less than or
equal to a TerminalAccessClass configuration attribute.
10. The apparatus as claimed in claim 7, characterized in that
means for determining the probe power as a function of
InitialAccessPower, ProbeRampUpStepSize and ProbeNumber.
Description
CLAIM OF PRIORITY UNDER 35 U.S.C. .sctn.119
[0001] The present Application for Patent claims priority to
Provisional Application Ser. No. 60/731,037, entitled "METHODS AND
APPARATUS FOR PROVIDING MOBILE BROADBAND WIRELESS HIGHER MAC",
filed Oct. 27, 2005, assigned to the assignee hereof, and expressly
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates generally to wireless
communications and more particularly to methods and apparatus for
transmission of an access probe by an access terminal.
[0004] 2. Background
[0005] Wireless communication systems have become a prevalent means
by which a majority of people worldwide have come to communicate.
Wireless communication devices have become smaller and more
powerful in order to meet consumer needs and to improve portability
and convenience. The increase in processing power in mobile devices
such as cellular telephones has lead to an increase in demands on
wireless network transmission systems. Such systems typically are
not as easily updated as the cellular devices that communicate
there over. As mobile device capabilities expand, it can be
difficult to maintain an older wireless network system in a manner
that facilitates fully exploiting new and improved wireless device
capabilities.
[0006] Wireless communication systems generally utilize different
approaches to generate transmission resources in the form of
channels. These systems may be code division multiplexing (CDM)
systems, frequency division multiplexing (FDM) systems, and time
division multiplexing (TDM) systems. One commonly utilized variant
of FDM is orthogonal frequency division multiplexing (OFDM) that
effectively partitions the overall system bandwidth into multiple
orthogonal subcarriers. These subcarriers may also be referred to
as tones, bins, and frequency channels. Each subcarrier can be
modulated with data. With time division based techniques, a each
subcarrier can comprise a portion of sequential time slices or time
slots. Each user may be provided with a one or more time slot and
subcarrier combinations for transmitting and receiving information
in a defined burst period or frame. The hopping schemes may
generally be a symbol rate hopping scheme or a block hopping
scheme.
[0007] Code division based techniques typically transmit data over
a number of frequencies available at any time in a range. In
general, data is digitized and spread over available bandwidth,
wherein multiple users can be overlaid on the channel and
respective users can be assigned a unique sequence code. Users can
transmit in the same wide-band chunk of spectrum, wherein each
user's signal is spread over the entire bandwidth by its respective
unique spreading code. This technique can provide for sharing,
wherein one or more users can concurrently transmit and receive.
Such sharing can be achieved through spread spectrum digital
modulation, wherein a user's stream of bits is encoded and spread
across a very wide channel in a pseudo-random fashion. The receiver
is designed to recognize the associated unique sequence code and
undo the randomization in order to collect the bits for a
particular user in a coherent manner.
[0008] A typical wireless communication network (e.g., employing
frequency, time, and/or code division techniques) includes one or
more base stations that provide a coverage area and one or more
mobile (e.g., wireless) terminals that can transmit and receive
data within the coverage area. A typical base station can
simultaneously transmit multiple data streams for broadcast,
multicast, and/or unicast services, wherein a data stream is a
stream of data that can be of independent reception interest to a
mobile terminal. A mobile terminal within the coverage area of that
base station can be interested in receiving one, more than one or
all the data streams transmitted from the base station. Likewise, a
mobile terminal can transmit data to the base station or another
mobile terminal. In these systems the bandwidth and other system
resources are assigned utilizing a scheduler.
[0009] The signals, signal formats, signal exchanges, methods,
processes, and techniques disclosed herein may provide several
advantages over known approaches. These may include, for example,
reduced signaling overhead, improved system throughput, increased
signaling flexibility, reduced information processing, reduced
transmission bandwidth, reduced bit processing, increased
robustness, improved efficiency, and reduced transmission
power.
SUMMARY
[0010] The following presents a simplified summary of one or more
aspects in order to provide a basic understanding of such aspects.
This summary is not an extensive overview of all contemplated
aspects, and is intended to neither identify key or critical
elements of all aspects nor delineate the scope of any or all
aspects. Its sole purpose is to present some concepts of one or
more aspects in a simplified form as a prelude to the more detailed
description that is presented later.
[0011] According to an embodiment, a method is described for
transmitting an access probe by an access terminal. The method
comprising determining a ProbeSequenceNumber, determining an
AccessSequenceID and adding the AccessSequenceID to public data,
when ProbeNumber is greater than MaxProbesPerSequence, performing
the following setting the ProbeNumber to `1`, incrementing the
ProbeSequence Number by 1, determining an AccessCarrier by
monitoring LoadControl bits on different carriers, using overhead
parameters corresponding to a selected Access Carrier, and adding
the AccessCarrier to the public data, determining a
DelayToNextProbe value, starting a timer for the DelayToNextProbe
frames, determining an InitialProbePower value, transmitting a
probe using AccessSequenceID, PilotPN, AccessCarrier and Power, and
incrementing the ProbeNumber.
[0012] According to another embodiment, a computer-readable medium
is described having a first set of instructions for determining a
ProbeSequenceNumber, a second set of instructions for determining
an AccessSequenceID and adding it to public data, a third set of
instructions for, when ProbeNumber is greater than
MaxProbesPerSequence, setting the ProbeNumber to `1`, incrementing
the ProbeSequence Number by 1, determining an AccessCarrier by
monitoring LoadControl bits on different carriers, using overhead
parameters corresponding to selected Access Carrier, and adding the
AccessCarrier to the public data, a fourth set of instructions for
determining a DelayToNextProbe value, a fifth set of instructions
for starting a timer for the DelayToNextProbe frames, a sixth set
of instructions for determining an InitialProbePower value, a
seventh set of instructions for transmitting a probe using
AccessSequinceID, PilotPN, AccessCarrier and Power, and an eighth
set of instructions for incrementing the ProbeNumber.
[0013] According to yet another embodiment, an apparatus is
described which includes a means for determining a
ProbeSequenceNumber, means for determining an AccessSequenceID and
adding it to a public data, means for determining ProbeNumber
greater than MaxProbesPerSequence, means for setting the
ProbeNumber to `1`, means for incrementing the ProbeSequence Number
by 1, means for determining an AccessCarrier by monitoring
LoadControl bits on different carriers, means for using overhead
parameters corresponding to selected Access Carrier for the
remainder of the procedures, and means for adding the AccessCarrier
to the public data, means for determining a DelayToNextProbe value,
means for starting a timer for the DelayToNextProbe frames, means
for determining an InitialProbePower value, means for transmitting
a probe using AccessSequinceID, PilotPN, AccessCarrier and Power,
and means for incrementing the ProbeNumber.
[0014] To the accomplishment of the foregoing and related ends, the
one or more aspects comprise the features hereinafter fully
described and particularly pointed out in the claims. The following
description and the annexed drawings set forth in detail certain
illustrative aspects of the one or more aspects. These aspects are
indicative, however, of but a few of the various ways in which the
principles of various aspects may be employed and the described
aspects are intended to include all such aspects and their
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates aspects of a multiple access wireless
communication system;
[0016] FIG. 2 illustrates aspects of a transmitter and receiver in
a multiple access wireless communication system;
[0017] FIGS. 3A and 3B illustrate aspects of superframe structures
for a multiple access wireless communication system;
[0018] FIG. 4 illustrates aspect of a communication between an
access terminal and access network;
[0019] FIGS. 5A and 5B illustrate a flow diagram of a process by
access terminal; and
[0020] FIG. 5C illustrates one or more processors for transmitting
an access probe.
DETAILED DESCRIPTION
[0021] Various aspects are now described with reference to the
drawings, wherein like reference numerals are used to refer to like
elements throughout. In the following description, for purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of one or more aspects. It may be
evident, however, that such aspect(s) may be practiced without
these specific details. In other instances, well-known structures
and devices are shown in block diagram form in order to facilitate
describing one or more aspects.
[0022] Referring to FIG. 1, a multiple access wireless
communication system according to one aspect is illustrated. A
multiple access wireless communication system 100 includes multiple
cells, e.g. cells 102, 104, and 106. In the aspect of FIG. 1, each
cell 102, 104, and 106 may include an access point 150 that
includes multiple sectors. The multiple sectors are formed by
groups of antennas each responsible for communication with access
terminals in a portion of the cell. In cell 102, antenna groups
112, 114, and 116 each correspond to a different sector. In cell
104, antenna groups 118, 120, and 122 each correspond to a
different sector. In cell 106, antenna groups 124, 126, and 128
each correspond to a different sector.
[0023] Each cell includes several access terminals which are in
communication with one or more sectors of each access point. For
example, access terminals 130 and 132 are in communication base
142, access terminals 134 and 136 are in communication with access
point 144, and access terminals 138 and 140 are in communication
with access point 146.
[0024] Controller 130 is coupled to each of the cells 102, 104, and
106. Controller 130 may contain one or more connections to multiple
networks, e.g. the Internet, other packet based networks, or
circuit switched voice networks that provide information to, and
from, the access terminals in communication with the cells of the
multiple access wireless communication system 100. The controller
130 includes, or is coupled with, a scheduler that schedules
transmission from and to access terminals. In other aspects, the
scheduler may reside in each individual cell, each sector of a
cell, or a combination thereof.
[0025] As used herein, an access point may be a fixed station used
for communicating with the terminals and may also be referred to
as, and include some or all the functionality of, a base station, a
Node B, or some other terminology. An access terminal may also be
referred to as, and include some or all the functionality of, a
user equipment (UE), a wireless communication device, terminal, a
mobile station or some other terminology.
[0026] It should be noted that while FIG. 1, depicts physical
sectors, i.e. having different antenna groups for different
sectors, other approaches may be utilized. For example, utilizing
multiple fixed "beams" that each cover different areas of the cell
in frequency space may be utilized in lieu of, or in combination
with physical sectors. Such an approach is depicted and disclosed
in co-pending U.S. patent application Ser. No. 11/260,895, entitled
"Adaptive Sectorization in Cellular System."
[0027] Referring to FIG. 2, a block diagram of an aspect of a
transmitter system 210 and a receiver system 250 in a MIMO system
200 is illustrated. At transmitter system 210, traffic data for a
number of data streams is provided from a data source 212 to
transmit (TX) data processor 214. In an aspect, each data stream is
transmitted over a respective transmit antenna. TX data processor
214 formats, codes, and interleaves the traffic data for each data
stream based on a particular coding scheme selected for that data
stream to provide coded data.
[0028] The coded data for each data stream may be multiplexed with
pilot data using OFDM, or other orthogonalization or
non-orthogonalization techniques. The pilot data is typically a
known data pattern that is processed in a known manner and may be
used at the receiver system to estimate the channel response. The
multiplexed pilot and coded data for each data stream is then
modulated (i.e., symbol mapped) based on one or more particular
modulation schemes (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for
that data stream to provide modulation symbols. The data rate,
coding, and modulation for each data stream may be determined by
instructions performed on provided by processor 230.
[0029] The modulation symbols for all data streams are then
provided to a TX processor 220, which may further process the
modulation symbols (e.g., for OFDM). TX processor 220 then provides
N.sub.T modulation symbol streams to N.sub.T transmitters (TMTR)
222a through 222t. Each transmitter 222 receives and processes a
respective symbol stream to provide one or more analog signals, and
further conditions (e.g., amplifies, filters, and upconverts) the
analog signals to provide a modulated signal suitable for
transmission over the MIMO channel. N.sub.T modulated signals from
transmitters 222a through 222t are then transmitted from N.sub.T
antennas 224a through 224t, respectively.
[0030] At receiver system 250, the transmitted modulated signals
are received by N.sub.R antennas 252a through 252r and the received
signal from each antenna 252 is provided to a respective receiver
(RCVR) 254. Each receiver 254 conditions (e.g., filters, amplifies,
and downconverts) a respective received signal, digitizes the
conditioned signal to provide samples, and further processes the
samples to provide a corresponding "received" symbol stream.
[0031] An RX data processor 260 then receives and processes the
N.sub.R received symbol streams from N.sub.R receivers 254 based on
a particular receiver processing technique to provide N.sub.T
"detected" symbol streams. The processing by RX data processor 260
is described in further detail below. Each detected symbol stream
includes symbols that are estimates of the modulation symbols
transmitted for the corresponding data stream. RX data processor
260 then demodulates, deinterleaves, and decodes each detected
symbol stream to recover the traffic data for the data stream. The
processing by RX data processor 218 is complementary to that
performed by TX processor 220 and TX data processor 214 at
transmitter system 210.
[0032] RX data processor 260 may be limited in the number of
subcarriers that it may simultaneously demodulate, e.g. 512
subcarriers or 5 MHz, and such a receiver should be scheduled on a
single carrier. This limitation may be a function of its FFT range,
e.g. sample rates at which the processor 260 may operate, the
memory available for FFT, or other functions available for
demodulation. Further, the greater the number of subcarriers
utilized, the greater the expense of the access terminal.
[0033] The channel response estimate generated by RX processor 260
may be used to perform space, space/time processing at the
receiver, adjust power levels, change modulation rates or schemes,
or other actions. RX processor 260 may further estimate the
signal-to-noise-and-interference ratios (SNRs) of the detected
symbol streams, and possibly other channel characteristics, and
provides these quantities to a processor 270. RX data processor 260
or processor 270 may further derive an estimate of the "operating"
SNR for the system. Processor 270 then provides channel state
information (CSI), which may comprise various types of information
regarding the communication link and/or the received data stream.
For example, the CSI may comprise only the operating SNR. In other
aspects, the CSI may comprise a channel quality indicator (CQI),
which may be a numerical value indicative of one or more channel
conditions. The CSI is then processed by a TX data processor 278,
modulated by a modulator 280, conditioned by transmitters 254a
through 254r, and transmitted back to transmitter system 210.
[0034] At transmitter system 210, the modulated signals from
receiver system 250 are received by antennas 224, conditioned by
receivers 222, demodulated by a demodulator 240, and processed by a
RX data processor 242 to recover the CSI reported by the receiver
system. The reported CSI is then provided to processor 230 and used
to (1) determine the data rates and coding and modulation schemes
to be used for the data streams and (2) generate various controls
for TX data processor 214 and TX processor 220. Alternatively, the
CSI may be utilized by processor 270 to determine modulation
schemes and/or coding rates for transmission, along with other
information. This may then be provided to the transmitter which
uses this information, which may be quantized, to provide later
transmissions to the receiver.
[0035] Processors 230 and 270 direct the operation at the
transmitter and receiver systems, respectively. Memories 232 and
272 provide storage for program codes and data used by processors
230 and 270, respectively.
[0036] At the receiver, various processing techniques may be used
to process the N.sub.R received signals to detect the N.sub.T
transmitted symbol streams. These receiver processing techniques
may be grouped into two primary categories (i) spatial and
space-time receiver processing techniques (which are also referred
to as equalization techniques); and (ii) "successive
nulling/equalization and interference cancellation" receiver
processing technique (which is also referred to as "successive
interference cancellation" or "successive cancellation" receiver
processing technique).
[0037] While FIG. 2 discusses a MIMO system, the same system may be
applied to a multi-input single-output system where multiple
transmit antennas, e.g. those on a base station, transmit one or
more symbol streams to a single antenna device, e.g. a mobile
station. Also, a single output to single input antenna system may
be utilized in the same manner as described with respect to FIG.
2.
[0038] The transmission techniques described herein may be
implemented by various means. For example, these techniques may be
implemented in hardware, firmware, software, or a combination
thereof. For a hardware implementation, the processing units at a
transmitter may be implemented within one or more application
specific integrated circuits (ASICs), digital signal processors
(DSPs), digital signal processing devices (DSPDs), programmable
logic devices (PLDs), field programmable gate arrays (FPGAs),
processors, controllers, micro-controllers, microprocessors,
electronic devices, other electronic units designed to perform the
functions described herein, or a combination thereof. The
processing units at a receiver may also be implemented within one
or more ASICs, DSPs, processors, and so on.
[0039] For a software implementation, the transmission techniques
may be implemented with modules (e.g., procedures, functions, and
so on) that perform the functions described herein. The software
codes may be stored in a memory (e.g., memory 230, 272x or 272y in
FIG. 2) and executed by a processor (e.g., processor 232, 270x or
270y). The memory may be implemented within the processor or
external to the processor.
[0040] It should be noted that the concept of channels herein
refers to information or transmission types that may be transmitted
by the access point or access terminal. It does not require or
utilize fixed or predetermined blocks of subcarriers, time periods,
or other resources dedicated to such transmissions.
[0041] Referring to FIGS. 3A and 3B, aspects of superframe
structures for a multiple access wireless communication system are
illustrated. FIG. 3A illustrates aspects of superframe structures
for a frequency division duplexed (FDD) multiple access wireless
communication system, while FIG. 3B illustrates aspects of
superframe structures for a time division duplexed (TDD) multiple
access wireless communication system. The superframe preamble may
be transmitted separately for each carrier or may span all of the
carriers of the sector.
[0042] In both FIGS. 3A and 3B, the forward link transmission is
divided into units of superframes. A superframe may consist of a
superframe preamble followed by a series of frames. In an FDD
system, the reverse link and the forward link transmission may
occupy different frequency bandwidths so that transmissions on the
links do not, or for the most part do not, overlap on any frequency
subcarriers. In a TDD system, N forward link frames and M reverse
link frames define the number of sequential forward link and
reverse link frames that may be continuously transmitted prior to
allowing transmission of the opposite type of frame. It should be
noted that the number of N and M may be vary within a given
superframe or between superframes.
[0043] In both FDD and TDD systems each superframe may comprise a
superframe preamble. In certain aspects, the superframe preamble
includes a pilot channel that includes pilots that may be used for
channel estimation by access terminals, a broadcast channel that
includes configuration information that the access terminal may
utilize to demodulate the information contained in the forward link
frame. Further acquisition information such as timing and other
information sufficient for an access terminal to communicate on one
of the carriers and basic power control or offset information may
also be included in the superframe preamble. In other cases, only
some of the above and/or other information may be included in this
superframe preamble.
[0044] As shown in FIGS. 3A and 3B, the superframe preamble is
followed by a sequence of frames. Each frame may consist of a same
or a different number of OFDM symbols, which may constitute a
number of subcarriers that may simultaneously utilized for
transmission over some defined period. Further, each frame may
operate according to a symbol rate hopping mode, where one or more
non-contiguous OFDM symbols are assigned to a user on a forward
link or reverse link, or a block hopping mode, where users hop
within a block of OFDM symbols. The actual blocks or OFDM symbols
may or may not hop between frames.
[0045] FIG. 4 illustrates transmission of an access probe 410 by an
access terminal 402 to an access network 404. Using a communication
link 406 and based upon predetermined timing, system conditions, or
other decision criteria, the access terminal 402 may transmit the
access probe to the access network 404. The communication link
between the access network 404 and access terminal 402 may be
implemented using communication protocols/standards such as World
Interoperability for Microwave Access (WiMAX), infrared protocols
such as Infrared Data Association (IrDA), short-range wireless
protocols/technologies, Bluetooth.RTM. technology, ZigBee.RTM.
protocol, ultra wide band (UWB) protocol, home radio frequency
(HomeRF), shared wireless access protocol (SWAP), wideband
technology such as a wireless Ethernet compatibility alliance
(WECA), wireless fidelity alliance (Wi-Fi Alliance), 802.11 network
technology, public switched telephone network technology, public
heterogeneous communications network technology such as the
Internet, private wireless communications network, land mobile
radio network, code division multiple access (CDMA), wideband code
division multiple access (WCDMA), universal mobile
telecommunications system (UMTS), advanced mobile phone service
(AMPS), time division multiple access (TDMA), frequency division
multiple access (FDMA), orthogonal frequency division multiple
(OFDM), orthogonal frequency division multiple access (OFDMA),
orthogonal frequency division multiple FLASH (OFDM-FLASH), global
system for mobile communications (GSM), single carrier (1X) radio
transmission technology (RTT), evolution data only (EV-DO)
technology, general packet radio service (GPRS), enhanced data GSM
environment (EDGE), high speed downlink data packet access (HSPDA),
analog and digital satellite systems, and any other
technologies/protocols that may be used in at least one of a
wireless communications network and a data communications
network.
[0046] The procedures and methods required for transmitting the
access probe 410 by the access terminal 402 or to receive the
access probe 410 at access network 404 is controlled by Default
Access Channel MAC protocol. The access terminal 402 may
incorporate the access probe 410 into a data packet 412 and the
data packet 412 is transmitted on the forward link 406.
[0047] FIGS. 5A & 5B illustrate a flow diagram of process 500,
according at an embodiment. Referring to FIG. 5A, at 502 it is
determined whether a ProbeSequenceNumber is greater than
MaxProbeSequences. If the condition is satisfied, at 504 an access
grant timer is set for T.sub.ACMPANProbeTimeoout duration and the
process ends. In case the above condition is not satisfied, the
access terminal performs the subsequent steps. At 506 an
AccessSequenceID is determined and added to the public data at
508.
[0048] At 510 it is determined whether a ProbeNumber is greater
than MaxProbesPerSequence. If the condition is satisfied then at
512 a Probe Number is set to `1`, at 514 the Probe Sequence Number
is incremented by 1 and at 516 an AccessCarrier is determined by
monitoring the LoadControl bits on the different carriers. For the
remainder of the procedures, the access terminal may use overhead
parameters corresponding to the selected AccessCarrier.
[0049] At 518 the AccessCarrier is added to the public data.
Referring to FIG. 5B, at 520, it is determined if the ProbeNumber
is 1. If the ProbeNumber is 1, at 524 a DelayToNextProbe is
determined by determining probe sequence backoff time, otherwise,
at 522 the DelayToNextProbe is set to an AccessCycleDuration. At
526, a timer for DelayToNextProbe frames is started. At 528, it is
determined whether a frame satisfy the requirement that a
ReverseLinkSilenceDuration and a ReverseLinkSilencePeriod for a
current sector is not active in the frame and a superframe
containing that frame has the LoadControl bits transmitted on the
Control Channel MAC is set to a value less than or equal to the
TerminalAccessClass configuration attribute. If the above condition
is not satisfied then at 530 the timer for the frame is not
decremented. If the said condition is satisfied, then at 532 the
timer in the frame is decremented and at 534 the process proceeds
to the next step after the expiry of the timer. At 536 an
InitialProbePower value is calculated. At 538, a probe is
transmitted using AccessSequenceId, PilotPN, Access Carrier and
Power where the power being calculated as
ProbePower=InitialAccessPower+ProbeRampUpStepSize*(ProbeNumber-1).
At 540 the ProbeNumber is incremented and at 542 the process
returns to process 502.
[0050] FIG. 5C illustrates a processor 550 for transmitting an
access probe by the access terminal to the access network. The
processors referred to may be electronic devices and may comprise
one or more processors configured for transmitting the access probe
according to the embodiment. Processor 552 is configured for
determining if the ProbeSequenceNumber is greater than
MaxProbeSequences. If the condition is satisfied, processor 554 is
configured for setting an access grant timer for
T.sub.ACMPANProbeTimeoout duration and ending the process.
Processor 556 is configured for determining an AccessSequenceID and
processor 558 is configured for adding it to the public data.
[0051] Further, processor 560 is configured for determining whether
a ProbeNumber is greater than MaxProbesPerSequence. If the
condition is satisfied then processor 562 is configured for setting
Probe Number to `1`. A processor 564 is configured for incrementing
Probe Sequence Number by 1 and a processor 566 is configured for
determining an AccessCarrier by monitoring the LoadControl bits on
the different carriers.
[0052] Further, a processor 568 is configured for adding the
AccessCarrier to the public data. A processor 570 is configured for
determining whether the ProbeNumber is 1. A processor 574 is
configured for determining DelayToNextProbe by determining probe
sequence backoff time. Another processor 572 is configured for
setting the DelayToNextProbe to the AccessCycleDuration. Processor
576 is configured for starting a timer for DelayToNextProbe frames
and processor 578 is configured for determining whether a frame
satisfies the requirement that a ReverseLinkSilenceDuration and a
ReverseLinkSilencePeriod for a current sector is not active in the
frame and the superframe containing that frame having the
LoadControl bits transmitted on the Control Channel MAC is set to a
value less than or equal to the TerminalAccessClass configuration
attribute. If the said condition is not satisfied then a processor
580 is configured for ceasing the decrement of timer for the frame.
If the said condition is satisfied then a processor 582 is
configured for decrementing the timer in the frame and a processor
584 is configured for proceeding to the next step after the expiry
of the timer. Processor 586 is configured for determining
InitialProbePower. A processor 588 is configured for using
AccessSequenceID, PilotPN, Access Carrier and Power where the power
being calculated as
ProbePower=InitialAccessPower+ProbeRampUpStepSize*(ProbeNumber-1).
A processor 590 is configured for incrementing the ProbeNumber and
a processor 592 is configured for restarting the process 500. The
functionality of the discrete processors 552 to 592 depicted in the
figure may be combined into a single processor 594. A memory 596 is
also coupled to the processor 594.
[0053] In an embodiment, an apparatus is described which includes
means for configured for determining if the ProbeSequenceNumber is
greater than MaxProbeSequences. If the condition is satisfied, a
means is provided for setting an access grant timer for
T.sub.ACMPANProbeTimeoout duration and ending the process. The
apparatus further comprises a means for determining an
AccessSequenceID and a means for adding it to the public data.
[0054] Further, a means is provided for determining whether a
ProbeNumber is greater than MaxProbesPerSequence. If the condition
is satisfied then a means is provided for setting Probe Number to
`1`. A means is provided for incrementing Probe Sequence Number by
1 and a means is provided for determining an AccessCarrier by
monitoring the LoadControl bits on the different carriers.
[0055] Further, the apparatus comprises a means is provided for
adding the AccessCarrier to the public data, means for determining
whether the ProbeNumber is 1, means for determining
DelayToNextProbe by determining probe sequence backoff time and a
means for setting the DelayToNextProbe to the AccessCycleDuration.
a means is provided for starting a timer for DelayToNextProbe
frames and a means is provided for determining whether a frame
satisfies the requirement that a ReverseLinkSilenceDuration and a
ReverseLinkSilencePeriod for a current sector is not active in the
frame and the superframe containing that frame having the
LoadControl bits transmitted on the Control Channel MAC is set to a
value less than or equal to the TerminalAccessClass configuration
attribute. If the said condition is not satisfied then a means is
provided for ceasing the decrement of timer for the frame. If the
said condition is satisfied then a means is provided for
decrementing the timer in the frame and a means is provided for
proceeding to the next step after the expiry of the timer. A means
is provided for determining InitialProbePower. A means is provided
for using AccessSequenceID, PilotPN, Access Carrier and Power where
the power being calculated as
ProbePower=InitialAccessPower+ProbeRampUpStepSize*(ProbeNumber-1).
A means is provided for incrementing the ProbeNumber and a means is
provided for restarting the process. The means described herein may
comprise one or more processors.
[0056] Furthermore, embodiments may be implemented by hardware,
software, firmware, middleware, microcode, or any combination
thereof. When implemented in software, firmware, middleware or
microcode, the program code or code segments to perform the
necessary tasks may be stored in a machine readable medium such as
a separate storage(s) not shown. A processor may perform the
necessary tasks. A code segment may represent a procedure, a
function, a subprogram, a program, a routine, a subroutine, a
module, a software package, a class, or any combination of
instructions, data structures, or program statements. A code
segment may be coupled to another code segment or a hardware
circuit by passing and/or receiving information, data, arguments,
parameters, or memory contents. Information, arguments, parameters,
data, etc. may be passed, forwarded, or transmitted via any
suitable means including memory sharing, message passing, token
passing, network transmission, etc
[0057] Various modifications to these aspects will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other aspects. Thus, the
description is not intended to be limited to the aspects shown
herein but is to be accorded the widest scope consistent with the
principles and novel features disclosed herein.
* * * * *