U.S. patent application number 14/658453 was filed with the patent office on 2015-07-09 for dual base stations for wireless communication systems.
This patent application is currently assigned to INTEL CORPORATION. The applicant listed for this patent is INTEL CORPORATION. Invention is credited to Hongseok Kim, Muthaiah Venkatachalam, Xiangying Yang.
Application Number | 20150195801 14/658453 |
Document ID | / |
Family ID | 42310649 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150195801 |
Kind Code |
A1 |
Kim; Hongseok ; et
al. |
July 9, 2015 |
DUAL BASE STATIONS FOR WIRELESS COMMUNICATION SYSTEMS
Abstract
A network apparatus comprises a controller to determine a first
base station for transmitting data and to determine a second
different base station for receiving data. In one embodiment, the
network apparatus further comprises a transceiver to transmit data
to the first base station while associated with the second base
station. The transceiver is operable to receive data from the
second base station while associated with the first base
station.
Inventors: |
Kim; Hongseok; (Hillsboro,
OR) ; Yang; Xiangying; (Portland, OR) ;
Venkatachalam; Muthaiah; (Beaverton, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTEL CORPORATION |
Santa Clara |
CA |
US |
|
|
Assignee: |
INTEL CORPORATION
Santa Clara
CA
|
Family ID: |
42310649 |
Appl. No.: |
14/658453 |
Filed: |
March 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12494145 |
Jun 29, 2009 |
9001783 |
|
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14658453 |
|
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61142582 |
Jan 5, 2009 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04W 52/48 20130101;
Y02D 70/166 20180101; Y02D 70/1262 20180101; Y02D 70/142 20180101;
H04W 52/0209 20130101; H04W 88/08 20130101; Y02D 30/70 20200801;
Y02D 70/1246 20180101; Y02D 70/144 20180101; Y02D 70/22 20180101;
Y02D 70/1244 20180101; Y02D 70/1242 20180101; Y02D 70/164 20180101;
H04W 72/0426 20130101; Y02D 70/1224 20180101; H04W 76/10 20180201;
H04W 48/20 20130101; Y02D 70/168 20180101; Y02D 70/146
20180101 |
International
Class: |
H04W 52/48 20060101
H04W052/48; H04W 72/04 20060101 H04W072/04; H04W 52/02 20060101
H04W052/02 |
Claims
1-21. (canceled)
22. A method to connect with two Evolved Node B (eNB) stations
simultaneously, comprising: associating with a first eNB to receive
downlink transmissions from the first eNB except to only transmit
control data to the first eNB; and associating with a second eNB
for uplink transmissions to the second eNB except to only receive
control data from the second eNB.
23. The method as claimed in claim 22, further comprising:
receiving automatic repeat request (ARQ) transmissions over the
downlink from the first eNB and transmitting an acknowledgment to
the first eNB as the control data in response to received ARQ
transmissions; and sending ARQ transmissions over the uplink to the
second eNB and receiving an acknowledgment from the second eNB as
the control data in response to the sent ARQ transmissions.
24. The method as claimed in claim 23, wherein the ARQ
transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
25. A user equipment to connect with two Evolved Node B (eNB)
stations simultaneously, comprising: a controller to associate with
a first eNB for downlink transmissions, and to associate with a
second eNB for uplink transmissions; and a transceiver to receive
downlink transmissions from the first eNB except to only transmit
control data to the eNB, and to transmit uplink transmissions to
the second eNB except to receive control data from the second
eNB.
26. The user equipment as claimed in claim 25, wherein the
transceiver is configured to receive automatic repeat request (ARQ)
transmissions over the downlink from the first eNB and to transmit
an acknowledgment to the first eNB as the control data in response
to received ARQ transmissions, and to send ARQ transmissions over
the uplink to the second eNB and to receive an acknowledgment from
the second eNB as the control data in response to the sent ARQ
transmissions.
27. The user equipment as claimed in claim 26, wherein the ARQ
transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
28. A non-transitory medium having instructions stored thereon
that, if executed, result in connecting with two Evolved Node B
(eNB) stations simultaneously, by: associating with a first eNB to
receive downlink transmissions from the first eNB except to only
transmit control data to the first eNB; and associating with a
second eNB for uplink transmissions to the second eNB except to
only receive control data from the second eNB.
29. The non-transitory medium as claimed in claim 28, wherein the
instructions, if executed further result connecting with two
Evolved Node B (eNB) stations simultaneously by: receiving
automatic repeat request (ARQ) transmissions over the downlink from
the first eNB and transmitting an acknowledgment to the first eNB
as the control data in response to received ARQ transmissions; and
sending ARQ transmissions over the uplink to the second eNB and
receiving an acknowledgment from the second eNB as the control data
in response to the sent ARQ transmissions.
30. The non-transitory medium as claimed in claim 29, wherein the
ARQ transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
31. A method to connect with two Evolved Node B (eNB) stations
simultaneously, comprising: determining a first eNB to transmit
data over an uplink channel; determining a second eNB to receive
data over a downlink channel; transmitting data to the first eNB
over the uplink channel without being associated with the first eNB
for the downlink channel; and receiving data from the second eNB
over the downlink channel without being associated with the second
eNB for the uplink channel.
32. The method of claim 31, further comprising: establishing a
first link, with a lower bandwidth than the uplink channel, to
receive only first network control data from the first eNB; and
establishing a second link, with a lower bandwidth than the
downlink channel, to transmit only second network control data to
the second eNB.
33. The method as claimed in claim 31, further comprising:
receiving automatic repeat request (ARQ) transmissions over the
downlink from the first eNB and transmitting an acknowledgment to
the first eNB as the control data in response to received ARQ
transmissions; and sending ARQ transmissions over the uplink to the
second eNB and receiving an acknowledgment from the second eNB as
the control data in response to the sent ARQ transmissions.
34. The method as claimed in claim 33, wherein the ARQ
transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
35. A user equipment to connect with two Evolved Node B (eNB)
stations simultaneously, comprising: a control to determine a first
eNB to transmit data over an uplink channel, and to determine a
second eNB to receive data over a downlink channel; and a
transceiver to transmit data to the first eNB over the uplink
channel without being associated with the first eNB for the
downlink channel, and to receive data from the second eNB over the
downlink channel without being associated with the second eNB for
the uplink channel.
36. The user equipment of claim 35, wherein the transceiver is
configured to establish a first link, with a lower bandwidth than
the uplink channel, to receive only first network control data from
the first eNB, and to establish a second link, with a lower
bandwidth than the downlink channel, to transmit only second
network control data to the second eNB.
37. The user equipment as claimed in claim 35, wherein the
transceiver is configured to receive automatic repeat request (ARQ)
transmissions over the downlink from the first eNB and transmitting
an acknowledgment to the first eNB as the control data in response
to received ARQ transmissions, and to send ARQ transmissions over
the uplink to the second eNB and receiving an acknowledgment from
the second eNB as the control data in response to the sent ARQ
transmissions.
38. The user equipment as claimed in claim 37, wherein the ARQ
transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
39. A non-transitory medium comprising instructions stored thereon
that, if executed, result in connecting with two Evolved Node B
(eNB) stations simultaneously, by: determining a first eNB to
transmit data over an uplink channel; determining a second eNB to
receive data over a downlink channel; transmitting data to the
first eNB over the uplink channel without being associated with the
first eNB for the downlink channel; and receiving data from the
second eNB over the downlink channel without being associated with
the second eNB for the uplink channel.
40. The non-transitory medium of claim 39, wherein the
instructions, if executed further result in connecting with two
Evolved Node B (eNB) stations simultaneously by: establishing a
first link, with a lower bandwidth than the uplink channel, to
receive only first network control data from the first eNB; and
establishing a second link, with a lower bandwidth than the
downlink channel, to transmit only second network control data to
the second eNB.
41. The non-transitory medium as claimed in claim 39, wherein the
instructions, if executed further result in connecting with two
Evolved Node B (eNB) stations simultaneously by: receiving
automatic repeat request (ARQ) transmissions over the downlink from
the first eNB and transmitting an acknowledgment to the first eNB
as the control data in response to received ARQ transmissions; and
sending ARQ transmissions over the uplink to the second eNB and
receiving an acknowledgment from the second eNB as the control data
in response to the sent ARQ transmissions.
42. The non-transitory medium as claimed in claim 41, wherein the
ARQ transmissions comprise hybrid automatic repeat request (HARQ)
transmissions.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/142,582, filed on Jan. 5, 2009, entitled
"Advanced Wireless Communication Systems and Techniques", and the
contents of which incorporated herein by reference as if set forth
herein in full.
TECHNICAL FIELD
[0002] Embodiments of the invention relate to data communication;
more particularly, embodiments of the invention relates to managing
connections to base stations.
BACKGROUND
[0003] It is becoming increasingly common to find broadband
wireless networking capabilities (e.g., IEEE 802.11, 802.16e, etc.)
in mobile devices. In many network environments, a network device
establishes communication with an access point, e.g., a base
station of a cellular network, for both uplink and downlink
access.
[0004] Wireless communication interfaces may use up a large portion
of total power supply available to mobile devices operating on
batteries. Power management schemes are used in conjunction with
network devices to extend the battery lifetime of mobile
communication devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Embodiments of the present invention will be understood more
fully from the detailed description given below and from the
accompanying drawings of various embodiments of the invention,
which, however, should not be taken to limit the invention to the
specific embodiments, but are for explanation and understanding
only.
[0006] FIG. 1 is a block diagram showing dual base stations system
in accordance with one embodiment of the invention.
[0007] FIG. 2 shows a block diagram of a network apparatus in
accordance with one embodiment of the invention.
[0008] FIG. 3 is a block diagram showing costs of connectivity of a
communication system in accordance with one embodiment of the
invention.
[0009] FIG. 4a shows an embodiment of a system communicating
control data without using a backbone connection.
[0010] FIG. 4b is an embodiment of a system communicating control
data with the use of a backbone connection.
[0011] FIG. 5 is a flow diagram of one embodiment of a process to
determine a base station for an uplink transmission and a base
station for a downlink transmission.
[0012] FIG. 6 is a diagram representation of a wireless
communication system in accordance with one embodiment of the
invention.
[0013] FIG. 7 illustrates a computer system for use with one
embodiment of the present invention.
DETAILED DESCRIPTION
[0014] In the following description, numerous details are set forth
to provide a more thorough explanation of embodiments of the
present invention. It will be apparent, however, to one skilled in
the art, that embodiments of the present invention may be practiced
without these specific details. In other instances, well-known
structures and devices are shown in block diagram form, rather than
in detail, in order to avoid obscuring embodiments of the present
invention.
[0015] Some portions of the detailed descriptions which follow are
presented in terms of algorithms and symbolic representations of
operations on data bits within a computer memory. These algorithmic
descriptions and representations are the means used by those
skilled in the data processing arts to most effectively convey the
substance of their work to others skilled in the art. An algorithm
is here, and generally, conceived to be a self-consistent sequence
of steps leading to a desired result. The steps are those requiring
physical manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at
times, principally for reasons of common usage, to refer to these
signals as bits, values, elements, symbols, characters, terms,
numbers, or the like.
[0016] It should be borne in mind, however, that all of these and
similar terms are to be associated with the appropriate physical
quantities and are merely convenient labels applied to these
quantities. Unless specifically stated otherwise as apparent from
the following discussion, it is appreciated that throughout the
description, discussions utilizing terms such as "processing" or
"computing" or "calculating" or "determining" or "displaying" or
the like, refer to the action and processes of a computer system,
or similar electronic computing device, that manipulates and
transforms data represented as physical (electronic) quantities
within the computer system's registers and memories into other data
similarly represented as physical quantities within the computer
system memories or registers or other such information storage,
transmission or display devices.
[0017] Embodiments of present invention also relate to apparatuses
for performing the operations herein. Some apparatuses may be
specially constructed for the required purposes, or it may comprise
a general purpose computer selectively activated or reconfigured by
a computer program stored in the computer. Such a computer program
may be stored in a computer readable storage medium, such as, but
not limited to, any type of disk including floppy disks, optical
disks, CD-ROMs, DVD-ROMs, and magnetic-optical disks, read-only
memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs,
NVRAMs, magnetic or optical cards, or any type of media suitable
for storing electronic instructions, and each coupled to a computer
system bus.
[0018] The algorithms and displays presented herein are not
inherently related to any particular computer or other apparatus.
Various general purpose systems may be used with programs in
accordance with the teachings herein, or it may prove convenient to
construct more specialized apparatus to perform the required method
steps. The required structure for a variety of these systems will
appear from the description below. In addition, embodiments of the
present invention are not described with reference to any
particular programming language. It will be appreciated that a
variety of programming languages may be used to implement the
teachings of the invention as described herein.
[0019] A machine-readable medium includes any mechanism for storing
or transmitting information in a form readable by a machine (e.g.,
a computer). For example, a machine-readable medium includes read
only memory ("ROM"); random access memory ("RAM"); magnetic disk
storage media; optical storage media; flash memory devices;
etc.
[0020] The method and apparatus described herein are for
determining base stations for wireless network transmissions.
Specifically, determining a base station for transmitting data
(uplink) based on distances of base stations is primarily discussed
in reference to mobile devices. However, the methods and apparatus
for determining a base station for an uplink transmission based on
distances of base stations is not so limited, as it may be
implemented on or in association with any integrated circuit device
or system, such as cell phones, personal digital assistants,
embedded controllers, mobile platforms, desktop platforms, and
server platforms, as well as in conjunction with other resources,
such as hardware/software threads.
[0021] The following inventive embodiments may be used in a variety
of applications including transmitters and receivers of a radio
system. Radio systems specifically included within the scope of the
present invention include, but are not limited to, network
interface cards (NICs), network adaptors, mobile stations, base
stations, access points (APs), hybrid coordinators (HCs), gateways,
bridges, hubs, routers, relay stations, repeaters, analog
repeaters, and amplify and forward repeaters. Further, the radio
systems within the scope of the invention may include cellular
radio telephone systems, satellite systems, personal communication
systems (PCS), two-way radio systems, and two-way pagers as well as
computing devices including radio systems such as personal
computers (PCs) and related peripherals, personal digital
assistants (PDAs), personal computing accessories, and all existing
and future arising systems which may be related in nature and to
which the principles of the inventive embodiments could be suitably
applied.
[0022] While the following detailed description may describe
example embodiments of the present invention in relation to
wireless metropolitan area networks (WMANs) or other wireless wide
area networks (WWANs), the embodiments are not limited thereto and
can be applied to other types of wireless networks where similar
advantages may be obtained. Such networks for which inventive
embodiments may be applicable specifically include, wireless
personal area networks (WPANs), wireless local area networks
(WLANs), WWANs such as cellular networks, or combinations of any of
these networks. Further, inventive embodiments may be discussed in
reference to wireless networks utilizing Orthogonal Frequency
Division Multiplexing (OFDM) modulation. However, the embodiments
of present invention are not limited thereto and, for example, the
embodiments can be implemented using other modulation or coding
schemes where suitably applicable.
Overview
[0023] FIG. 1 is a block diagram showing dual base stations system
in accordance with one embodiment of the invention. In one
embodiment, a network apparatus associates with two different base
stations for uplink (transmitting data from the apparatus) and
downlink transmissions (receiving data by the apparatus) to improve
downlink capacity and to reduce uplink transmit power of the
network apparatus.
[0024] Referring to FIG. 1, in one embodiment, communication
network 100 comprises relay station 130, base station 140, mobile
stations 104-106, and networks 112. In one embodiment, boundary 120
and boundary 122 logically splits coverage area of mobile station
104 into 3 zones (zone A 150, zone B 151, and zone C 152).
[0025] It will be appreciated by those of ordinary skill that FIG.
1 is a linear model of communication network 100. The coverage area
is shown as divided linearly by boundaries 120 and 122 which are
not necessarily linear in an actual network. For example, in some
embodiments, boundary 120 forms a part of a network cell boundary.
In one embodiment, boundary 122 is a locus of points approximately
equidistant from relay station 130 and base station 140. Boundary
120 is a locus of points with approximately equal downlink signal
strength values (or receive power values) at the mobile station 104
with respect to receiving data from relay station 130 and from base
station 140. Zones (zones 150-152) and boundaries (e.g., boundaries
120 and 122) are shown in block diagram form, rather than in
detail, in order to avoid obscuring embodiments of the present
invention.
[0026] In one embodiment, base station 140 is an access point. In
one embodiment, base station 140 performs association
authentication and time/frequency resource allocation. In one
embodiment, base station 140 is either main, relay, or remote base
station. A main base station is connected with the wired Ethernet.
A relay base station relays data between remote base stations,
wireless clients, or other relay stations to a base station. A
remote base station accepts connections from wireless clients and
passes the clients to relay or main stations.
[0027] In one embodiment, relay station 130 amplifies and forwards
communications from mobile station 104 to network 112. In one
embodiment, relay station 130 has capabilities similar to base
station 140. In one embodiment, relay station 130 acts a base
station to provide backward-compatible functionalities to legacy
subscriber stations. In this case, backhaul link(s) between base
station 140 and relay station 130 is concealed from legacy
subscriber stations. In one embodiment, relay station 130 is a base
station similar to base station 140. In one embodiment, relay
station 130 is not connected directly to a core network (e.g., 112)
by electrical or wires or optical cables but rather are connected
to the core network via a wireless backhaul (not shown) to base
station 140. In one embodiment, relay station 130 is referred to as
a "micro" or "pico" base station.
[0028] In one embodiment, mobiles stations 104-106 are also known
as subscriber stations. In one embodiment, mobile stations 104-106
include any combination of stationary devices, mobile devices, and
portable wireless communication devices, such as, for example,
personal digital assistants (PDAs), laptops or portable computers
with wireless communication capability, web tablets, wireless
telephones, wireless headsets, pagers, instant messaging devices,
digital cameras, televisions, medical devices (e.g., a heart rate
monitor, a blood pressure monitor, etc.), or other devices that
communicate information wirelessly.
[0029] In one embodiment, base station 140 communicates, using
radio-frequency (RF) signals, with mobile stations 104-106 allowing
mobile stations 104-106 to communicate amongst each other as well
as allowing mobile stations 104-106 to communicate with external
networks 112 (e.g., the Internet).
[0030] In one embodiment, mobile station 104 is a standard range
mobile station. In one embodiment, mobile station 106 is an
extended range mobile station. An extended range encompasses a much
larger geographic area than the standard range. In one embodiment,
a standard range extends up to a couple hundred meters in an
unobstructed environment (e.g., outdoors) from base station 140
while the extended range extends up to a thousand or more meters in
an unobstructed environment from base station 140. In one
embodiment, values of transmit power and antenna heights of
wireless transceivers in relay stations 130 are less than those of
base stations 140, whereas those of mobile stations 104 are even
less.
[0031] In one embodiment, in conjunction with heterogeneous overlay
network deployment, mobile station 104 uses two different base
stations (e.g., base station 140, relay station 130) for downlink
and uplink transmissions. In one embodiment, rather than selecting
one access point only based on signal to interference/noise ratio
(SINR) at the mobile station 104, mobile station 104 associates
with two different access points for uplink and downlink
transmissions to improve the downlink capacity and to reduce the
uplink transmit power of mobile station 104. In one embodiment,
SINR at the mobile station 104 is measured with respect to downlink
reference signals (e.g., preamble and pilot).
[0032] In one embodiment, mobile station 104 selects the two access
points based on two criteria. In one embodiment, a first criterion
is based on a value indicative of maximum downlink SINR (maxSINR)
of signal received at mobile station 104. A higher downlink maxSINR
results in a higher downlink capacity (to mobile station 104). In
one embodiment, a second criterion is based on minimum uplink
transmit power at the mobile station 104 for an uplink transmission
(from mobile station 104). In one embodiment, a minimum uplink
transmit power is referred to as a required transmission power. A
lower uplink transmit power consumption extends battery lifetime of
mobile station 104. In one embodiment, mobile station 104 selects a
downlink transmission based on the first criterion and selects an
uplink transmission based on the second criterion.
[0033] In one embodiment, if base stations 130 and 140 are similar
in antenna configuration, channels from mobile station 104 to these
two base stations show similar scaling properties (for example,
channel gain changes in the distance from a base station) such that
selecting a minimum uplink transmission power is approximated by
selecting a base station with the closest distance. In one
embodiment, if the above conditions do not hold, the uplink
transmission power is affected by factors including distances, the
configuration of an antenna, etc.
[0034] In one embodiment, a minimal uplink transmission power is
estimated by considering the ratio of a downlink reference signal's
receive power (e.g. SINR) at mobile station 104 versus a known
transmission power (for example, from base station broadcast),
assuming that uplink/downlink channels are symmetry in terms of
channel gains. In one embodiment, mobile station 104 performs
explicit signaling with any target base station to obtain necessary
information related to uplink transmission power. The following
examples related to "closest distance" are described by way of
illustration and is in no way intended to be considered
limiting.
[0035] In one embodiment, SINR is defined as signal power divided
by a sum of interference power and noise power, wherein signal
power is a product of transmission power and channel gain. In one
embodiment, a transmission capacity is an upper bound on the amount
of information that is reliably transmitted over a communication
connection (in terms of bit per second). In one embodiment, a
transmission capacity of a connection is approximately equal to a
value of bandwidth multiplied by log(1+SINR). In one embodiment, a
higher SINR results in a higher transmission capacity as explained
above. In one embodiment, a higher transmission power results in a
higher SINR and therefore higher transmission capacity.
[0036] In one embodiment, if downlink and uplink transmissions
(also referred to as channels, connections, etc.) are symmetric and
all base stations (access points) use a same transmit power value,
selecting a base station based on either a downlink maxSINR value
or a minimum uplink transmit power value yields to the same base
station. In one embodiment, if base stations operate on different
values of transmit power (in a heterogeneous network, e.g., IEEE
802.16m network), mobile station 104 will associate with two
different base stations (one for uplink transmission and one for
downlink transmission) when mobile station 104 operates in a dual
access point zone (DAZ). In one embodiment, transmit power of a
base station 140 is 46 dBm, whereas, transmit power of relay
station 130 is 36 dBm in accordance with an 802.16m network.
[0037] In one embodiment, the transmit power of relay station 130
is lower than the transmit power of base station 140. Referring to
the example shown in FIG. 1, cell boundary 120 is closer to relay
station 130 because cell boundary 120 is selected based on maximum
received SINR values of different base stations measured with
respect to mobile station 104. On the other hand, if mobile station
104 selects a base station based on minimum transmit power, mobile
station 104 selects a closer base station (in terms of distance)
such that the cell boundary is at the middle (as indicated by
boundary 122).
[0038] In one embodiment, cell boundary 120 is referred to herein
as a downlink cell boundary. In one embodiment, cell boundary 122
is referred to herein as an uplink cell boundary.
[0039] In one embodiment, mobile station 104 associates with the
same base station (i.e., relay station 130) for uplink and downlink
transmissions while mobile station 104 is located in zone A 150. In
one embodiment, mobile station 104 associates with the same base
station (i.e., base station 140) for uplink and downlink
transmissions while mobile station 104 is located in zone C 152. In
one embodiment, mobile station 104 associates with the two base
stations (i.e., relay station 130 for an uplink transmission and
base station 140 for a downlink transmission) while mobile station
104 is located in zone B 151. In one embodiment, zone B 151 is also
referred to herein as a dual AP zone (DAZ), where mobile station
104 associates with two different access points.
[0040] In one embodiment, if the cell coverage of base station 140
and relay station 130 is determined based on a downlink perspective
only (i.e., maximum received SINR at the mobile station 104),
mobile station 104 selects a base station with a better downlink
transmission capacity. The selected base station however may not be
a better base station for uplink transmission if the distance of
the base station from mobile station 104 is greater and mobile
station 104 needs to use high transmit power to establish a uplink
connection to the base station.
[0041] In one embodiment, a significant gain on system capacity and
power saving at mobile station 104 are observed if mobile station
104 is able to use different base stations when operating in DAZ.
In one embodiment, if the difference of transmit power of base
station 140 and relay station 130 is 10 dB, mobile station 104 is
able to save upto 70% of uplink transmit power on average, if
compared to performing both downlink/uplink communications with
base station 140.
Communication Systems
[0042] In one embodiment, base station 140 is a Wireless Fidelity
(WiFi) access point. In one embodiment, base station 140 operates
in accordance with one or more of the Institute of Electrical and
Electronic Engineers (IEEE) 802.11 standards (e.g., IEEE 802.11(a),
802.11(b), 802.11(g), 802.11(h), and 802.11(n)), variations, or
evolutions thereof.
[0043] In one embodiment, communication network 100 is a broadband
wireless access (BWA) network and base station 140 is a Worldwide
Interoperability for Microwave Access (WiMax) base station or other
broadband communication station. In one embodiment, base station
140 operates in accordance with one or more of the Institute of
Electrical and Electronic Engineers (IEEE) 802.16 standards,
variations, or evolutions thereof.
[0044] In one embodiment, communication network 100 is a wireless
local area network (WLAN). In one embodiment, wireless
communication network 100 is a wireless personal area network
(WPAN), a wireless metropolitan area network (WMAN), a wireless
wide area network (WWAN), 3GPP2, 3G LTE, or 4G network. In one
embodiment, mobile stations 104-106 operate in a carrier sense
multiple access (CSMA) mode.
[0045] In one embodiment, base station 140 communicates with mobile
stations 104-106 using spread-spectrum signals within one or more
frequency spectrums. In other embodiments, base station 140
communicates using orthogonal frequency division multiplexed (OFDM)
communication signals within one or more frequency spectrums. In
one embodiment, base station 140 communicates with mobile stations
104-106 selectively using either spread-spectrum signals or OFDM
communication signals. The OFDM signals comprise a plurality of
orthogonal subcarriers.
[0046] In one embodiment, the frequency spectrums used by base
station 140 comprise either a 5 GHz frequency spectrum or a 2.4 GHz
frequency spectrum. In one embodiment, 5 GHz frequency spectrum
includes frequencies ranging from approximately 4.9 to 5.9 GHz, and
2.4 GHz spectrum includes frequencies ranging from approximately
2.3 to 2.5 GHz, although the scope of the invention is not limited
in this respect, as other frequency spectrums are also equally
suitable. In some BWA network embodiments, the frequency spectrum
for communications comprises frequencies between 2 and 11 GHz,
although the scope of the invention is not limited in this
respect.
[0047] In one embodiment, antennas of base station 140 and antennas
of mobile stations 104-106 comprise one or more directional or
omnidirectional antennas including for example, dipole antennas,
monopole antennas, patch antennas, loop antennas, microstrip
antennas, or other types of antennas suitable for transmission of
RF signals. In one embodiment, base station 140, and mobile
stations 104-106 use two or more antennas each. In one embodiment,
instead of the two or more antennas, a single antenna with multiple
apertures is used.
[0048] FIG. 2 shows a block diagram of a network apparatus in
accordance with one embodiment of the invention. Many related
components such as data buses and peripherals have not been shown
to avoid obscuring the invention. Referring to FIG. 2, in one
embodiment, network apparatus 260 comprises controller 261,
transceiver 262, memory 265, and selection logic 263. In one
embodiment, network apparatus 260 communicates with base station
270 and base station 271.
[0049] In one embodiment, controller 261 monitors network
parameters, such as, for example: SINR values with respect to
different transmissions (of different base stations), approximate
distances from base stations (for example via average path loss
calculation), transmit power, and capacities of connections. In one
embodiment, controller 261 controls operations of network apparatus
260. In one embodiment, memory 265 stores programs to be executed
by controller 261.
[0050] In one embodiment, transceiver 262 includes physical (PHY)
layer circuitry for communicating with the physical mediums
(wireless or otherwise), media access control (MAC) layer
circuitry, and higher-level layer (HLL) circuitry. In one
embodiment, PHY layer circuitry, MAC layer circuitry, and HLL
circuitry comprise functionality for both receiver and transmitter
operations and include processing circuitry to evaluate
communications from network apparatus 260, among other things. In
one embodiment, transceiver 262 is connected to a core network,
such as an Internet protocol (IP) network, via a wireless
connection, a physical wired connection (e.g., electrical or fiber
optic connection), or both.
[0051] In one embodiment, selection logic 263 selects base stations
(e.g., base stations 270-271) based on two criteria. In one
embodiment, a first criterion is based on a value indicative of
maximum SINR (maxSINR) of signal received (e.g., downlink reference
signal). A second criterion is based on minimum transmit power for
an uplink transmission from network apparatus 260. In one
embodiment, selection logic 263 selects a downlink transmission (to
network apparatus 260) based on the first criterion and selects an
uplink transmission based on the second criterion.
[0052] In one embodiment, network apparatus 260 comprises, for
example, client devices and network points of attachments. In one
embodiment, network apparatus 260 is fixed, stationary, or mobile
depending on the particular environment or implementation and
communicates over the medium of free space generally referred to as
the "air interface" (e.g., wireless shared media).
[0053] In one embodiment, network apparatus 260 comprises wireless
devices that comply with or operate in accordance with one or more
protocols, such as, for example, WiFi, Bluetooth, UWB, WiMAX, and
cellular protocols. Network apparatus 260 comprises, but is not
necessarily limited to, a computer, server, workstation, laptop,
ultra-laptop, handheld computer, telephone, cellular telephone,
personal digital assistant (PDA), router, switch, bridge, hub,
gateway, wireless device, multi-network, multiple integrated radio
devices, mixed-network device supporting multiple concurrent
radios, WiFi plus cellular telephone, portable digital music
player, pager, two-way pager, mobile subscriber station, printer,
camera, enhanced video and voice device, and any other one-way or
two-way device capable of communicating with other devices or base
stations. The embodiments are not limited in this context.
[0054] FIG. 3 is a block diagram showing costs of connectivity of a
communication system in accordance with one embodiment of the
invention. Referring to FIG. 3, a communication system comprises
base station 310, mobile station 330, and relay station 320. It
will be appreciated by those of ordinary skill that other relay
stations and base stations that present in the communication system
are not shown to avoid obscuring embodiments of the present
invention.
[0055] In a network that supports dual AP zone (DAZ), costs induced
from additional hops via relay stations (e.g., 343) are determined
with one of the following methods. In one embodiment, mobile
station 330 selects to use a connection to base station 310 rather
than a connection via relay station 320 to avoid the additional
relay cost.
[0056] In one embodiment, a relay network is based on IEEE 802.16m
where the delay of wireless backhaul connection (backbone
connection) between base station 310 and relay station 320 is small
and predictable. In addition, MAC coordination between base station
310 and relay station 320 is easily managed by base station 310
because base station 310 is a traffic aggregation point of all
connected relay stations (including relay station 320).
[0057] Let C.sub.bm 340, C.sub.rm 341, and C.sub.br 341, be the
capacity of a transmit/receive pair of base station 310/mobile
station 330, relay station 320/mobile station 330, and base station
310/relay station 320, respectively. In one embodiment, a downlink
cell boundary (i.e., downlink to mobile station 330) between base
station 310 and relay station 320 is the position where the
following equation is satisfied.
1 C bm = 1 C br + 1 C rm ( 1 ) ##EQU00001##
[0058] In one embodiment, the inverse of capacity value
( e . g . , 1 C bm ) ##EQU00002##
is the 1-bit transmission time of a connection. For example,
1 C bm ##EQU00003##
represents 1-bit transmission time of the connection between base
station 310 and mobile station 330. In one embodiment, the 1-bit
transmission time of a direct connection
( 1 C bm ) ##EQU00004##
and 1-bit transmission time of a connection going through relay
station
320 ( 1 C br + 1 C rm ) ##EQU00005##
are approximately equal at the cell boundary.
[0059] Similarly, in determining an uplink cell boundary (i.e.
uplink from mobile station 330) between base station 310 and relay
station 320, let C.sub.mb, C.sub.mr, and C.sub.rb be the capacity
for a transmit/receive pair of mobile station 330/base station 320,
mobile station 330/relay station 320, and relay station 320/base
station 310, respectively. In one embodiment, a cell boundary for
the uplink transmission (from mobile station 330) is a position
where the following equation is satisfied:
1 C mb = 1 C mr + 1 C rb ( 2 ) ##EQU00006##
[0060] In one embodiment, base station 310 and relay station 330
are shared by multiple users. Equation (1) and equation (2) are
modified to include load of each base station to improve
temporally-fair scheduling. In the following equations, E(x)
represents the expected value (average or min) of a sample.
N.sup.d.sub.b represents a number of mobile stations associated
with base station 310 for a downlink transmission, whereas
N.sup.d.sub.r represents a number of mobile stations associated
with relay station 320 for a downlink transmission. N.sup.u.sub.b
represents a number of mobile stations associated with base station
310 for an uplink transmission, whereas N.sup.u.sub.r represents a
number of mobile stations associated with relay station 320 for an
uplink transmission.
[0061] In one embodiment, a cell boundary for the downlink
transmission (to mobile station 330) is a position where the
following equation is satisfied:
E [ N b d + 1 ] C bm = E [ N r d + 1 ] C br + E [ N r d + 1 ] C rm
( 3 ) ##EQU00007##
[0062] In one embodiment, a cell boundary for the uplink
transmission is a position where the following equation is
satisfied:
E [ N b u + 1 ] C mb = E [ N r u + 1 ] C rb + E [ N r u + 1 ] C mr
( 4 ) ##EQU00008##
[0063] In one embodiment, if N active mobile stations share a base
station, the effective transmission time of a user increases by
approximately N times because that user only uses 1/N fractional
time. In one embodiment, (N+1) is used in equation (3) and (4)
instead of N to reflect that this mobile station is a potential
additional mobile station which is going to join the network.
Control and Signaling
[0064] In one embodiment, uplink and downlink communications are
not fully independent of each other. For example, a mobile station
is required to request for transmission slots from a base station
(before sending data via an uplink transmission) in a cellular
network. In one embodiment, a base station grants transmission
slots by transmitting scheduling information to the mobile station
via a downlink control channel. In one embodiment, if hybrid
automatic repeat request (HARQ) is enabled, data transmission
requires acknowledgement to be sent immediately to the opposite
direction. Thus, good connectivity between neighboring base
stations is important even if uplink/downlink base stations are two
different base stations.
[0065] In one embodiment, efficient backbone communications
(backhaul communication) among base stations is performed together
with other advanced radio technologies, such as, for example,
collaborative multi-point MIMO (multiple-input multiple-output)
systems.
[0066] In one embodiment, transmission (e.g., in the downlink
direction) regarding scheduling information for an uplink
transmission is referred to herein as uplink control. In one
embodiment, transmission regarding scheduling information for a
downlink transmission is referred to herein as downlink
control.
[0067] In one embodiment, all other transmission of control data
via an uplink is referred to herein as uplink signaling. In one
embodiment, uplink signaling includes, but is not limited to,
ranging, HARQ feedback for downlink data, sounding, and channel
quality indicator (CQI) channel feedback. In one embodiment, all
other transmission of control data via a downlink is referred to
herein as downlink signaling. In one embodiment, downlink signaling
includes, but is not limited, system configuration broadcast and
HARQ feedback for uplink data.
[0068] FIG. 4a shows an embodiment of a system communicating
control/signaling data without using a backbone connection between
two base stations. Referring to FIG. 4a, in one embodiment, the
communication system comprises base station 410 base station 412,
mobile station 411, and several links. In one embodiment, base
station 412 is a base station. In one embodiment, mobile station
411 uses base station 410 as an uplink base station and uses base
station 412 as a downlink base station.
[0069] In one embodiment, mobile station 411 maintains at least
four links (two data links and two signaling links) with two base
stations (i.e., base stations 410-411). Each signaling link is
associated with a corresponding data link in a reverse
direction.
[0070] In one embodiment, thin downlink signaling 432 and uplink
control 431 data flows in a direction from base station 410 to
mobile station 411. Uplink data 430 data flow in a direction from
mobile station 411 towards base station 410. In one embodiment,
thin uplink signaling 442 data flows in a direction from mobile
station 411 towards base station 412. Downlink data 441 and
downlink control 440 data flow in a direction from base station 412
to mobile station 411.
[0071] In one embodiment, without a backbone connection,
control/signaling data are transmitted without going through a
relay station or a centralized system. In one embodiment,
coordination is required to prevent multiple links (e.g., from
mobile station 411 to base station 410) occur concurrently, because
mobile station 411 operates at low transmit power and the uplink
capacity is limited by the low transmit power.
[0072] FIG. 4b is an embodiment of a system communicating control
data with the use of a backbone connection. Referring to FIG. 4b,
in one embodiment, the communication system comprises base station
480, base station 482, mobile station 481, and several links. In
one embodiment, base station 482 is a base station. In one
embodiment, mobile station 481 uses base station 480 as an uplink
base station and uses base station 482 as a downlink base
station.
[0073] In one embodiment, mobile station 411 maintains at least two
links and a backbone link (wired or wireless). Each link transmits
data, signaling, control data, or any combination thereof.
[0074] In one embodiment, uplink signaling 460 and uplink data 461
share a link and the data flow in a direction from mobile station
481 to base station 480. In one embodiment, thin uplink control
472, downlink data 471, downlink control and signaling 470 share a
link and the data flow in a direction from base station 482 to
mobile station 411.
[0075] In one embodiment, in addition to the two links, there is a
backbone connection 450 established from base station 480 to base
station 482. In one embodiment, uplink control/signaling is
transferred from uplink base station (i.e., base station 481) to
downlink base station (i.e., base station 482) via backbone 450,
which then transmits to mobile station 481 with a small penalty on
latency. In one embodiment, backbone 450 is used to copy uplink
signaling (452) and to transfer uplink control request (453), from
base station 480 to base station 482.
[0076] In one embodiment, data that are timing critical (e.g., HARQ
feedback) are more suitable to be transmitted using a communication
system with respect to FIG. 4a. In one embodiment, data that are
less timing critical (e.g., uplink scheduling information, CQI
feedback, and uplink ranging) are transmitted using a communication
system with respect to either FIG. 4a or FIG. 4b. In one
embodiment, uplink scheduling information is managed at a base
station or is coordinated among multiple base stations.
[0077] FIG. 5 is a flow diagram of one embodiment of a process to
determine a base station for sending data (uplink transmission) and
a base station for receiving data (downlink transmission). The
process is performed by processing logic that may comprise hardware
(circuitry, dedicated logic, etc.), software (such as one that is
run on a general purpose computer system or a dedicated machine),
or a combination of both. In one embodiment, the process is
performed in conjunction with a network apparatus (e.g., network
apparatus with respect to FIG. 2). In one embodiment, the process
is performed by a computer system such as the computer system shown
in FIG. 7.
[0078] Referring to FIG. 5, in one embodiment, processing logic
begins by determining network parameters, such as, for example,
load associated with a base station, distance associated with each
base station, capacity of an connection (especially downlink
capacity), and a SINR value associated with an connection (process
block 500).
[0079] In one embodiment, processing logic selects base stations (a
first base station and a second base station) based on two criteria
related with the network parameters. In one embodiment, a first
criterion is based on a value indicative of maximum SINR (maxSINR)
of signal received. Processing logic determines a second criterion
based on the minimum transmit power for an uplink transmission of a
network device. In one embodiment, processing logic selects a
downlink transmission based on the first criterion and selects an
uplink transmission based on the second criterion (process block
510)
[0080] In one embodiment, processing logic establishes an uplink
transmission and a downlink transmission with a first base station
and a second base station respectively. In one embodiment,
processing logic transmits and receives data via the uplink and
downlink transmissions (process block 520).
[0081] FIG. 6 is a diagram representation of a wireless
communication system in accordance with one embodiment of the
invention. Referring to FIG. 6, in one embodiment, wireless
communication system 900 includes one or more wireless
communication networks, generally shown as 910, 920, and 930.
[0082] In one embodiment, the wireless communication system 900
includes a wireless personal area network (WPAN) 910, a wireless
local area network (WLAN) 920, and a wireless metropolitan area
network (WMAN) 930. In other embodiments, wireless communication
system 900 includes additional or fewer wireless communication
networks. For example, wireless communication network 900 includes
additional WPANs, WLANs, and/or WMANs. The methods and apparatus
described herein are not limited in this regard.
[0083] In one embodiment, wireless communication system 900
includes one or more subscriber stations (e.g., shown as 940, 942,
944, 946, and 948). For example, the subscriber stations 940, 942,
944, 946, and 948 include wireless electronic devices such as, for
example, a desktop computer, a laptop computer, a handheld
computer, a tablet computer, a cellular telephone, a pager, an
audio/video player (e.g., an MP3 player or a DVD player), a gaming
device, a video camera, a digital camera, a navigation device
(e.g., a GPS device), a wireless peripheral (e.g., a printer, a
scanner, a headset, a keyboard, a mouse, etc.), a medical device
(e.g., a heart rate monitor, a blood pressure monitor, etc.), and
other suitable fixed, portable, or mobile electronic devices. In
one embodiment, wireless communication system 900 includes more or
fewer subscriber stations.
[0084] In one embodiment, subscriber stations 940, 942, 944, 946,
and 948 use a variety of modulation techniques such as spread
spectrum modulation (e.g., direct sequence code division multiple
access (DS-CDMA), frequency hopping code division multiple access
(FH-CDMA), or both), time-division multiplexing (TDM) modulation,
frequency-division multiplexing (FDM) modulation, orthogonal
frequency-division multiplexing (OFDM) modulation, multi-carrier
modulation (MCM), other suitable modulation techniques, or
combinations thereof to communicate via wireless links.
[0085] In one embodiment, laptop computer 940 operates in
accordance with suitable wireless communication protocols that
require very low power, such as, for example, Bluetooth.TM.,
ultra-wide band (UWB), radio frequency identification (RFID), or
combinations thereof to implement the WPAN 910. In one embodiment,
laptop computer 940 communicates with devices associated with the
WPAN 910, such as, for example, video camera 942, printer 944, or
both via wireless links.
[0086] In one embodiment, laptop computer 940 uses direct sequence
spread spectrum (DSSS) modulation, frequency hopping spread
spectrum (FHSS) modulation, or both to implement the WLAN 920
(e.g., a basic service set (BSS) network in accordance with the
802.11 family of standards developed by the Institute of Electrical
and Electronic Engineers (IEEE) or variations and evolutions of
these standards). For example, laptop computer 940 communicates
with devices associated with the WLAN 920 such as printer 944,
handheld computer 946, smart phone 948, or combinations thereof via
wireless links.
[0087] In one embodiment, laptop computer 940 also communicates
with access point (AP) 950 via a wireless link. AP 950 is
operatively coupled to router 952 as described in further detail
below. Alternatively, AP 950 and router 952 may be integrated into
a single device (e.g., a wireless router).
[0088] In one embodiment, laptop computer 940 uses OFDM modulation
to transmit large amounts of digital data by splitting a radio
frequency signal into multiple small sub-signals, which in turn,
are transmitted simultaneously at different frequencies. In one
embodiment, laptop computer 940 uses OFDM modulation to implement
WMAN 930. For example, laptop computer 940 operates in accordance
with the 802.16 family of standards developed by IEEE to provide
for fixed, portable, mobile broadband wireless access (BWA)
networks (e.g., the IEEE std. 802.16, published 2004), or
combinations thereof to communicate with base stations, shown as
960, 962, and 964, via wireless link(s).
[0089] Although some of the above examples are described above with
respect to standards developed by IEEE, the methods and apparatus
disclosed herein are readily applicable to many specifications,
standards developed by other special interest groups, standard
development organizations (e.g., Wireless Fidelity (Wi-Fi)
Alliance, Worldwide Interoperability for Microwave Access (WiMAX)
Forum, Infrared Data Association (IrDA), Third Generation
Partnership Project (3GPP), etc.), or combinations thereof. The
methods and apparatus described herein are not limited in this
regard.
[0090] WLAN 920 and WMAN 930 are operatively coupled to network 970
(public or private), such as, for example, the Internet, a
telephone network (e.g., public switched telephone network (PSTN)),
a local area network (LAN), a cable network, and another wireless
network via connection to an Ethernet, a digital subscriber line
(DSL), a telephone line, a coaxial cable, any wireless connection,
etc., or combinations thereof.
[0091] In one embodiment, WLAN 920 is operatively coupled to
network 970 via AP 950 and router 952. In another embodiment, WMAN
930 is operatively coupled to network 970 via base station(s) 960,
962, 964, or combinations thereof. Network 970 includes one or more
network servers (not shown).
[0092] In one embodiment, wireless communication system 900
includes other suitable wireless communication networks, such as,
for example, wireless mesh networks, shown as 980. In one
embodiment, AP 950, base stations 960, 962, and 964 are associated
with one or more wireless mesh networks. In one embodiment, AP 950
communicates with or operates as one of mesh points (MPs) 990 of
wireless mesh network 980. In one embodiment, AP 950 receives and
transmits data in connection with one or more of MPs 990. In one
embodiment, MPs 990 include access points, redistribution points,
end points, other suitable connection points, or combinations
thereof for traffic flows via mesh paths. MPs 990 use any
modulation techniques, wireless communication protocols, wired
interfaces, or combinations thereof described above to
communicate.
[0093] In one embodiment, wireless communication system 900
includes a wireless wide area network (WWAN) such as a cellular
radio network (not shown). Laptop computer 940 operates in
accordance with other wireless communication protocols to support a
WWAN. In one embodiment, these wireless communication protocols are
based on analog, digital, or dual-mode communication system
technologies, such as, for example, Global System for Mobile
Communications (GSM) technology, Wideband Code Division Multiple
Access (WCDMA) technology, General Packet Radio Services (GPRS)
technology, Enhanced Data GSM Environment (EDGE) technology,
Universal Mobile Telecommunications System (UMTS) technology,
High-Speed Downlink Packet Access (HSDPA) technology, High-Speed
Uplink Packet Access (HSUPA) technology, other suitable generation
of wireless access technologies (e.g., 3G, 4G, etc.) standards
based on these technologies, variations and evolutions of these
standards, and other suitable wireless communication standards.
Although FIG. 6 depicts a WPAN, a WLAN, and a WMAN, In one
embodiment, wireless communication system 900 includes other
combinations of WPANs, WLANs, WMANs, and WWANs. The methods and
apparatus described herein are not limited in this regard.
[0094] In one embodiment, wireless communication system 900
includes other WPAN, WLAN, WMAN, or WWAN devices (not shown) such
as, for example, network interface devices and peripherals (e.g.,
network interface cards (NICs)), access points (APs),
redistribution points, end points, gateways, bridges, hubs, etc. to
implement a cellular telephone system, a satellite system, a
personal communication system (PCS), a two-way radio system, a
one-way pager system, a two-way pager system, a personal computer
(PC) system, a personal data assistant (PDA) system, a personal
computing accessory (PCA) system, other suitable communication
system, or combinations thereof.
[0095] In one embodiment, subscriber stations (e.g., 940, 942, 944,
946, and 948) AP 950, or base stations (e.g., 960, 962, and 964)
includes a serial interface, a parallel interface, a small computer
system interface (SCSI), an Ethernet interface, a universal serial
bus (USB) interface, a high performance serial bus interface (e.g.,
IEEE 1394 interface), any other suitable type of wired interface,
or combinations thereof to communicate via wired links. Although
certain examples have been described above, the scope of coverage
of this disclosure is not limited thereto.
[0096] Embodiments of the invention may be implemented in a variety
of electronic devices and logic circuits. Furthermore, devices or
circuits that include embodiments of the invention may be included
within a variety of computer systems. Embodiments of the invention
may also be included in other computer system topologies and
architectures.
[0097] FIG. 7 illustrates an example of a computer system in
conjunction with one embodiment of the invention. Processor 705
accesses data from level 1 (L1) cache memory 706, level 2 (L2)
cache memory 710, and main memory 715. In other embodiments of the
invention, cache memory 706 may be a multi-level cache memory
comprise of an L1 cache together with other memory such as an L2
cache within a computer system memory hierarchy and cache memory
710 are the subsequent lower level cache memory such as an L3 cache
or more multi-level cache. Furthermore, in other embodiments, the
computer system may have cache memory 710 as a shared cache for
more than one processor core.
[0098] In one embodiment, memory/graphic controller 716, IO
controller 717, or combinations thereof is integrated in processor
705. In one embodiment, parts of memory/graphic controller 716,
parts of IO controller 717, or combinations thereof is integrated
in processor 705.
[0099] Processor 705 may have any number of processing cores. Other
embodiments of the invention, however, may be implemented within
other devices within the system or distributed throughout the
system in hardware, software, or some combination thereof.
[0100] Main memory 715 may be implemented in various memory
sources, such as dynamic random-access memory (DRAM), hard disk
drive (HDD) 720, solid state disk 725 based on NVRAM technology, or
a memory source located remotely from the computer system via
network interface 730 or via wireless interface 740 containing
various storage devices and technologies. The cache memory may be
located either within the processor or in close proximity to the
processor, such as on the processor's local bus 707. Furthermore,
the cache memory may contain relatively fast memory cells, such as
a six-transistor (6T) cell, or other memory cell of approximately
equal or faster access speed.
[0101] Other embodiments of the invention, however, may exist in
other circuits, logic units, or devices within the system of FIG.
7. Furthermore, in other embodiments of the invention may be
distributed throughout several circuits, logic units, or devices
illustrated in FIG. 7.
[0102] The invention is not limited to the embodiments described,
but can be practiced with modification and alteration within the
spirit and scope of the appended claims. For example, it should be
appreciated that the present invention is applicable for use with
all types of semiconductor integrated circuit ("IC") chips.
Examples of these IC chips include but are not limited to
processors, controllers, chipset components, programmable logic
arrays (PLA), memory chips, network chips, or the like. Moreover,
it should be appreciated that exemplary sizes/models/values/ranges
may have been given, although embodiments of the present invention
are not limited to the same. As manufacturing techniques (e.g.,
photolithography) mature over time, it is expected that devices of
smaller size could be manufactured.
[0103] Whereas many alterations and modifications of the embodiment
of the present invention will no doubt become apparent to a person
of ordinary skill in the art after having read the foregoing
description, it is to be understood that any particular embodiment
shown and described by way of illustration is in no way intended to
be considered limiting. Therefore, references to details of various
embodiments are not intended to limit the scope of the claims which
in themselves recite only those features regarded as essential to
the invention.
* * * * *