U.S. patent application number 14/807293 was filed with the patent office on 2015-11-19 for method and apparatus for using direct wireless links and a central controller for dynamic resource allocation.
This patent application is currently assigned to INTERDIGITAL PATENT HOLDINGS, INC.. The applicant listed for this patent is InterDigital Patent Holdings, Inc.. Invention is credited to Martino Freda, Jean-Louis Gauvreau, Joseph M. Murray.
Application Number | 20150334563 14/807293 |
Document ID | / |
Family ID | 43526917 |
Filed Date | 2015-11-19 |
United States Patent
Application |
20150334563 |
Kind Code |
A1 |
Freda; Martino ; et
al. |
November 19, 2015 |
METHOD AND APPARATUS FOR USING DIRECT WIRELESS LINKS AND A CENTRAL
CONTROLLER FOR DYNAMIC RESOURCE ALLOCATION
Abstract
A method and apparatus may be used for short range multi-device
communications. The method and apparatus may be used in personal
area networks (PANs). The apparatus may transmit a security key
using a non-penetrating wavelength. The apparatus may establish a
secure communication and transmit data using a penetrating
wavelength. The data transmission may be encrypted.
Inventors: |
Freda; Martino; (Laval,
CA) ; Gauvreau; Jean-Louis; (La Prairie, CA) ;
Murray; Joseph M.; (Schwenksville, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Patent Holdings, Inc. |
Wilmington |
DE |
US |
|
|
Assignee: |
INTERDIGITAL PATENT HOLDINGS,
INC.
Wilmington
DE
|
Family ID: |
43526917 |
Appl. No.: |
14/807293 |
Filed: |
July 23, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14279681 |
May 16, 2014 |
9094166 |
|
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14807293 |
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|
12844306 |
Jul 27, 2010 |
8737323 |
|
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14279681 |
|
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|
61229109 |
Jul 28, 2009 |
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61301308 |
Feb 4, 2010 |
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Current U.S.
Class: |
398/115 |
Current CPC
Class: |
H04B 10/114 20130101;
H04W 76/14 20180201; H04J 14/0298 20130101; H04K 1/10 20130101;
H04L 9/0827 20130101; H04W 72/0433 20130101; H04L 63/18 20130101;
H04W 12/04 20130101; H04W 4/80 20180201; H04W 12/003 20190101; H04J
14/0221 20130101; H04L 5/0051 20130101 |
International
Class: |
H04W 12/04 20060101
H04W012/04; H04W 4/00 20060101 H04W004/00; H04L 9/08 20060101
H04L009/08; H04B 10/114 20060101 H04B010/114 |
Claims
1. A wireless transmit/receive unit (WTRU) comprising: a
transmitter configured to: transmit a security key to another WTRU
via a non-penetrating wavelength; and transmit data to the another
WTRU via a penetrating wavelength.
2. The WTRU of claim 1, wherein the non-penetrating wavelength is
ultraviolet (UV)-C.
3. The WTRU of claim 1, wherein the penetrating wavelength is
ultraviolet (UV)-A.
4. The WTRU of claim 1, wherein the penetrating wavelength is a
radio frequency (RF) wavelength.
5. The WTRU of claim 1, wherein the data is encrypted.
6. The WTRU of claim 1, wherein the security key is a private
key.
7. A wireless transmit/receive unit (WTRU) comprising: a receiver
configured to: receive a security key from another WTRU via a
non-penetrating wavelength; and receive data from the another WTRU
via a penetrating wavelength; and a processor configured to decode
the received data.
8. The WTRU of claim 7, wherein the non-penetrating wavelength is
ultraviolet (UV)-C.
9. The WTRU of claim 7, wherein the penetrating wavelength is
ultraviolet (UV)-A.
10. The WTRU of claim 7, wherein the penetrating wavelength is a
radio frequency (RF) wavelength.
11. The WTRU of claim 7, wherein the data is encrypted.
12. The WTRU of claim 7, wherein the security key is a private
key.
13. A method for use in a wireless transmit/receive unit (WTRU),
the method comprising: a transmitter configured to: transmit a
security key to another WTRU via a non-penetrating wavelength; and
transmit data to the another WTRU via a penetrating wavelength.
14. The method of claim 13, wherein the non-penetrating wavelength
is ultraviolet (UV)-C.
15. The method of claim 13, wherein the penetrating wavelength is
ultraviolet (UV)-A.
16. The method of claim 13, wherein the penetrating wavelength is a
radio frequency (RF) wavelength.
17. The method of claim 13, wherein the data is encrypted.
18. The method of claim 13, wherein the security key is a private
key.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/279,681, filed May 16, 2014, which is a
continuation of U.S. patent application Ser. No. 12/844,306, filed
on Jul. 27, 2010, now U.S. Pat. No. 8,737,323 granted on May 27,
2014, which claims the benefit of U.S. Provisional Application Ser.
No. 61/229,109, filed on Jul. 28, 2009, and U.S. Provisional
Application Ser. No. 61/301,308, filed on Feb. 4, 2010, hereby
incorporated by reference as if fully set forth.
FIELD OF INVENTION
[0002] This application is related to wireless communications.
BACKGROUND
[0003] Ultraviolet (UV) communication is a form of optical wireless
communication that operates in the UV band. This band of
electromagnetic (EM) radiation is located between visible light 150
and x-rays 160 in the EM spectrum 100. The location of UV in the EM
spectrum 100 is shown in FIG. 1.
[0004] Based on absorption properties of UV radiation in the
earth's atmosphere, the UV band is divided into four main
sub-bands. Vacuum UV (10 nm-200 nm) 110 is heavily absorbed by
oxygen molecules in the atmosphere. UV-C (200 nm-280 nm) 120 is
fully absorbed by the ozone layer and only exists on the earth's
surface through manmade sources. UV-B (280 nm-315 nm) 130 is
partially absorbed by the ozone layer and is the primary agent
responsible for sunburns. Finally, UV-A (315 nm-400 nm) 140 is not
absorbed by the ozone layer and constitutes 98.7% of the UV
radiation that reaches the earth's surface from the sun.
[0005] UV-C communication is preferably suited for short-range, low
power networking. The inherent security also makes this technology
ideal for networks that are used to communicate sensitive or
personal information. The fact that UV-C does not operate in the
radio frequency (RF) band allows it to be used in situations where
RF communication may create interference or could be dangerous
(e.g., hospitals, airplanes, refineries, chemical plants,
etc.).
[0006] UV-A has more relaxed exposure limits when compared with
UV-C, ranging from 300.times. to 13000.times., depending on the
UV-A wavelength. This may allow transmitters with higher powers to
be used in a personal communication system. When compared with
visible light, UV-A also has more relaxed laser exposure limits (up
to 20.times.) due to the fact that the human retina is not
sensitive to UV-A. UV-A maintains the security aspects of UV-C, as
it also does not penetrate through walls, and penetration through
regular glass is limited to wavelengths above .about.325 nm
(depending on the type of glass). Special transparent filters also
exist which allow UV-A to be blocked by glass all the way to the
start of the visible light spectrum (.about.400 nm).
[0007] With the proliferation of wireless devices, exchange of
information between devices during meetings has become a common
need. This data exchange must also be able to support large
bandwidths, such as in the case of projecting of a corporate
strategy video during a board meeting, or for rapid transfer of
large confidential documents between board member smart phones or
laptops. While wireless network security applications have been
developed with this in mind, wireless networks will remain highly
susceptible to eavesdropping as long as there is a means for an
eavesdropper to intercept network traffic. This is always possible
in the case of RF communications where this type of communication
medium cannot be confined to a closed room, where a secure meeting
generally takes place.
[0008] With the advent of new applications such as high resolution
video, the need for wireless technologies to support these new high
bandwidth applications has increased. However, many of the existing
personal area network (PAN) technologies today (such as Bluetooth,
which can achieve an expected 1-3 Mbps) lack these required data
rates.
[0009] Finally, as new technologies are deployed to allow for short
range indoor communication and as these technologies take advantage
of new or existing frequency bands, the chance for interference of
these new technologies with devices that are sensitive to RF
communications may increase. This may be true in the case of
equipment used in hospitals, airplanes, and chemical plants.
[0010] Technologies using 60 GHz, Terahertz, infrared 170, visible
light 150 and UV spectrum have the potential for solving each of
these issues or needs. It would be advantageous to share a secure
spectrum by multiple devices (each with its own security
requirements) while staying within the limits for safe transmission
power levels and minimizing interference using a physical layer
(PHY) that allows for flexible bandwidth allocation and power
control.
SUMMARY
[0011] A method and apparatus may be used for short range
multi-device communications. The method and apparatus may be used
in personal area networks (PANs). The apparatus may transmit a
security key using a non-penetrating wavelength. The apparatus may
establish a secure communication and transmit data using a
penetrating wavelength. The data transmission may be encrypted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings wherein:
[0013] FIG. 1 shows the location of UV in the EM spectrum;
[0014] FIG. 2a shows a high level block diagram of a UV personal
area network (PAN) with an access point (AP);
[0015] FIG. 2b shows a high level block diagram of a UV PAN without
an AP;
[0016] FIG. 3 shows a detailed example of a PAN network;
[0017] FIG. 4 shows a protocol stack based on 802.11;
[0018] FIG. 5 shows an OFDM-based spectrum allocation method;
[0019] FIG. 6 shows the main physical layer stages in a master
WTRU;
[0020] FIG. 7 shows a flow diagram of a channel sounding
process;
[0021] FIG. 8 shows a flow diagram of a security process;
[0022] FIG. 9 shows a flow diagram of an encryption process;
and
[0023] FIG. 10 shows a UV-enhanced 802.11 protocol stack for a
device that supports two PHY adaptations.
DETAILED DESCRIPTION
[0024] When referred to hereafter, the terminology "wireless
transmit/receive unit (WTRU)" includes but is not limited to a user
equipment (UE), a mobile station, a fixed or mobile subscriber
unit, a pager, a cellular telephone, a personal digital assistant
(PDA), a computer, or any other type of device capable of operating
in a wireless environment. When referred to hereafter, the
terminology "base station" includes but is not limited to a Node-B,
a site controller, an access point (AP), or any other type of
interfacing device capable of operating in a wireless
environment.
[0025] The properties of the electromagnetic (EM) spectrum that may
be of most interest from a security standpoint are range and the
ability to penetrate materials. As the frequency increases, the
range and the ability to penetrate materials may also decrease.
Technologies that lend themselves to secure short range
communications (SSRC), include but are not limited to: extremely
high frequency (EHF) (30-300 GHz), Terahertz (300-3000 GHz), and
Optical (infrared, visible light, and ultra violet (UV)) bands.
[0026] SSRC technologies, including but not limited to: EHF,
Terahertz and Optical, are types of EM radiation that exhibit
features that may be used to allow secure, high-bandwidth data
communication between WTRUs in a personal area network (PAN), local
area network (LAN), or machine-to-machine (M2M) network. Although
UV is described herein, any type of EM radiation that exhibits some
or all of the properties of SSRC technologies, including but not
limited to: EHF, Terahertz or Optical, may be used in the methods
and apparatus introduced herein to achieve secure high bandwidth
communication. In particular, several properties of EM radiation
are of interest. First, the ability to be confined within an
enclosure where the communication will take place, whether it is
via walls or other means. Next, the ability to provide
non-line-of-sight (NLOS) communication within that enclosure
despite the presence of obstacles. This may be achieved by
scattering, reflecting, or re-directing the EM radiation either
naturally off of walls or the wireless medium itself, or using
enabling devices such as reflectors. Finally, the ability to
provide large amounts of unlicensed bandwidth for use in
communication systems is of interest.
[0027] FIG. 2a is a high level block diagram of a PAN 200. An
orthogonal frequency division multiple access method (OFDMA) may be
used within the PAN. While UV is primarily shown in this figure,
radio frequency (RF), EHF, Terahertz and Optical technologies, may
also be used. The PAN may be located within a single room (Room 1).
A plurality of WTRUs exchanging data using direct UV links 280 may
be located within Room 1, along with an access point (AP) 230.
Device communication is realized using orthogonal
frequency-division multiplexing (OFDM) in order to make use of the
robustness to frequency selective fading and multiple access
capabilities.
[0028] The central controller (CC) 220 may be located in a location
other than Room 1 (e.g., Room 2). Communication between the WTRUs
and the CC may be through RF based radio access technology (RAT)
250, if the CC is located outside of Room 1.
[0029] Each room may also have its own AP 230, which may be
connected to all other APs in other rooms via a RF connection 270
through the CC 220. The AP 230 may be placed on the ceiling of the
room in order to ensure line-of-sight (LOS) communication with all
devices within the room, which may ensure a high bandwidth link to
the CC 220.
[0030] When a WTRU (e.g. WTRU1, master) 210 decides to set up a
direct link with another WTRU (e.g. WTRU2, responder) 240, WTRU1
210 sends a message to the AP 230 located in Room 1 via UV or via
RF 260. The AP 230 receives the message via UV or via RF 260. If
the message is received via UV, the AP converts the message to an
RF signal 270 in order to transmit it to the CC 220, located
outside of Room 1. Once the CC 220 receives the message, the CC 220
determines communication parameters such as allocating bandwidth
(i.e., OFDM subcarriers) and specific wavelengths for use by WTRU1
210 when communicating with WTRU2 240 within the PAN 200. This
information is transmitted to the AP 230 via an RF signal 270. The
AP 230 receives the message via RF 270 and may convert the message
to transmit it to WTRU1 210 and/or WTRU2 240 via UV 260 or may
transmit the message via RF. Once WTRU1 210 and/or WTRU2 240
receive the communication parameters WTRU1 210 establishes a UV
direct communication link 280 with WTRU2 240 in order to exchange
data.
[0031] Direct UV links, such as the link established between WTRU1
210 and WTRU2 240 may be used when high data rate and/or high
security point-to-point services may be required. The architecture
may comprise a standard RF link between the WTRU and the base
station and/or between the base station and the CC, and a direct UV
link between WTRUs. The RF link may be capable of penetrating
walls, thereby allowing the base station, WTRU and CC to be
physically located in different rooms. However, a direct UV link
may not be capable of penetrating walls, thereby requiring WTRUs
that form a direct UV link to be physically located in the same
room.
[0032] FIG. 2b is a high level block diagram of a UV PAN 200 where
a plurality of WTRUs exchanging data using direct UV links may be
located within Room 1 along with a CC 220. Communication between
the WTRUs and the CC 220 may be through UV or RF.
[0033] When a WTRU (e.g., WTRU1, master) 210 decides to set up a
direct link with another WTRU (e.g., WTRU2, responder) 240, WTRU1
210 sends a message to the CC 220, located in Room 1. The message
is sent directly to the CC 220 via UV or RF 260. Once the CC 220
receives the message, the CC 220 determines communication
parameters such as allocating bandwidth (i.e., OFDM subcarriers)
and specific wavelengths (i.e., UV-A or UV-C) for use by WTRU1 210
when communicating with WTRU2 240 within the PAN 200. This
information is transmitted directly to WTRU1 via UV or RF 260. Once
WTRU1 210 receives the communication parameters it establishes a UV
communication link 280 with WTRU2 240 in order to exchange
data.
[0034] FIG. 3 is a detailed example of a PAN 300. FIG. 3 may
include a plurality of WTRUs. Each WTRU may be capable of both UV
and RF communications and may include a RF antenna 305 and a UV
antenna 310 as well as a RF converter 308 to identify, track and
convert radio waves and an UV converter 312 to identify, track and
convert UV waves. In addition, each WTRU may include a processor
315, transmitter 317 and a receiver 319. Each WTRU may also be
equipped with multiple applications 320. When the CC 330 is located
in a different room, WTRUs may be required to support a UV air
interface for WTRU to WTRU communication and an 802.11 interface
for communication with the CC 330.
[0035] An AP 335 may also be included in the UV PAN 300. The AP 335
may be located in the same room as the plurality of WTRUs and may
be capable of both UV and RF communications. The AP may include a
RF antenna 337 and a UV antenna 339 as well as a RF converter 348
and an UV converter 346. In addition, the AP may include a
processor 340, transmitter 342 and a receiver 344.
[0036] A CC 330 may be included in the UV PAN 300. The CC 330 may
be located either within the same room as the plurality of WTRUs,
Room 1, or may be located in a location other than Room 1. The CC
330 may be capable of both UV and RF communications and may include
a RF antenna 332 and a UV antenna 334 as well as a RF converter 350
and an UV converter 352. The CC 330 may include a processor 358,
transmitter 356 and a receiver 354.
[0037] The CC 330 may also include a quality of security (QoSec)
database 360. The QoSec database may include a listing of WTRUs
within the vicinity of the CC 330 and a listing of each application
associated with each individual WTRU within the vicinity of the CC.
Each application for each WTRU is tagged with a level of security.
Alternatively, or in combination with providing a security level
for each application, a level of security may be assigned to a WTRU
itself. Each application associated with a WTRU that has been
assigned a level of security may be tagged with the WTRUs assigned
level of security. Alternatively, or in combination with the above,
WTRUs may be assigned to a group. A level of security may be
assigned to the group. WTRUs that are part of the same group may
all be tagged with a specified level of security. Each application
associated with a WTRU included in a group may be tagged with the
WTRUs assigned level of security. This may facilitate a set of
security classes for WTRUs operating on a network.
[0038] The levels of security may be defined as low, medium and
high or may include additional levels of granularity. Certain
security features may be associated with each level of security.
For example, applications requiring a high level of security, such
as those used to exchange encryption keys, may be allocated with
security features such as wavelengths in a band with propagation
characteristics that require transmissions to be contained within a
room. This may prevent the transmission from penetrating glass
windows. Applications requiring a low level of security, such as
communications after encryption, may be allocated with wavelengths
in a band that may penetrate walls. In addition, the level of
security and the security features associated with an application
may vary between WTRUs and groups of WTRUs. Alternatively, security
features may be assigned to a WTRU or a group of WTRUs.
[0039] The CC 330 may also include a capability database 362. The
capability database 362 may include a listing of WTRUs within the
vicinity of the CC 330 and specific information regarding each of
the WTRUs. The capability database 362 may also include information
regarding the PAN.
[0040] The capability database includes a data rate and specific
capability information for each WTRU and each device in the PAN.
The specific capability information may include but is not limited
to, the ability of each device to transmit using particular SSRC
technology, including but not limited to: EHF, Terahertz or Optical
wavelengths, the presence or absence of RF capabilities on the
device, and whether the device is equipped with directionality
capabilities. The capability database 362 may also include the
security class or classes associated with a device, namely the
amount of security that is guaranteed through transmission by the
device.
[0041] In addition to WTRU specific information, the capability
database 362 may also contain information about the total UV
radiation currently within the room where the WTRU resides and the
total amount of allowable exposure at each point in the room. This
information may be used by the CC 330 in order to determine how
devices communicate and to allocate UV spectrum or set transmission
(TX) power levels for WTRUs that request communication via a direct
link.
[0042] The CC may also include a vicinity database 364. The
vicinity database 364 may be built and maintained through
information obtained by the channel sounding procedure described
herein. The vicinity database 364 may include a listing of WTRUs
within the vicinity of the CC 330 and may include information
relating to the association of a WTRU to a particular room. The
vicinity database 364 may also include information that is needed
to determine if and how two WTRUs may communicate with each other.
This information may include directionality information (i.e., the
angle between two WTRUs or the angle between a WTRU and the CC 330)
and range information (i.e., whether a first WTRU is in the range
of a second WTRU and if either UV-A or UV-C is used by the
WTRU).
[0043] WTRU mobility properties, procedures and a mobility history
of the WTRU may be used by the channel sounding procedure and may
be included in the vicinity database 364. The vicinity database may
include mobility information such as how frequently a WTRU is moved
and may also contain channel estimates for the links between the CC
330 and the WTRUs.
[0044] The CC 330 may also include an allocation device 366. The
allocation device 366 may include a loading algorithm. The loading
algorithm may use OFDM to determine the allocation of subcarriers
and wavelengths (i.e., UV-A or UV-C) for each WTRU. The loading
algorithm may utilize the channel conditions or channel estimates
stored in the capability database to determine the allocation of
wavelengths for each WTRU. Channel estimates stored in the
capability database may be derived by the channel sounding
procedure and may be updated through the transmission of pilot
signals within the data during normal transmission within the
chosen wavelength.
[0045] Also considered by the loading algorithm for the allocation
of subcarriers and wavelengths, may be the maximum allowable
transmit power for each WTRU. The maximum allowable transmit power
may be based on both the WTRU's capabilities for transmitting on
that wavelength as well as the maximum safe exposure limits of UV-A
and UV-C within the room. This form of spectrum allocation may
ensure a maximum amount of flexibility in terms of security,
required data rate, and reliability of transmission in the presence
of interference from sunlight and other WTRUs. Subcarriers and
wavelengths may also be allocated with network assistance.
[0046] The CC 330 may include a channel sounding controller 368.
The channel sounding controller 368 controls the channel sounding
procedure, which is used to characterize the channel and determine
which WTRUs are within the vicinity of each other and within the
vicinity of the CC 330. The channel sounding procedure may be
triggered by many different events including but not limited to
when a request for association is made to the CC 330, when a
request to setup a direct link with another WTRU is made, upon the
expiration of a timer or in response to an asymmetric event.
[0047] An asymmetric event may include but is not limited to a user
request, a change in location of the WTRU due to mobility, or the
arrival/detection/departure of a new device in a room, in the
vicinity of the WTRU or in the range of the CC.
[0048] When the new device detects the presence of a CC, it
associates itself with the CC. Upon doing so, the CC may trigger
the channel sounding procedure, whereby the new device and other
devices in the vicinity may send a reference signal to the CC. This
process may determine the devices that may directly communicate
with the new device. The channel sounding procedure may also allow
updating of the vicinity and the capability databases based on the
presence of the new device. This may also trigger the readjustment
of the transmit powers and subcarrier allocations on ongoing direct
links in order to allow for communication between the new device
and other devices or the CC.
[0049] To alleviate the need for dual RAT support (both a RF and a
UV air interface), a local base station may be used inside of each
room. In this approach, the devices may support a UV-based air
interface and may communicate with the local base station using UV
signals. While direct UV links may be established between devices
within the same room, an RF link may be established between the
local base station and a CC located outside the room. In this
embodiment, the local base station may be both an RF-based WTRU
connected to the CC and a UV-based base station connected to the
UV-based WTRUs using a dual protocol stack based on 802.11 as shown
in FIG. 4.
[0050] FIG. 4 shows a UV-enhanced 802.11 protocol stack for a
device that supports UV 400. The 802.11_MAC 410 may extend the
capabilities of the standard 802.11 MAC by providing lower-MAC
functions that may be used to interface with the 802.11_PHY_UV
layer 420. The 802.11_PHY_UV 420 protocol may be based on an OFDM
air interface.
[0051] FIG. 5 shows an OFDM-based spectrum allocation method 500.
In FIG. 5, three UV-C bands 510 and two UV-A bands 520, each
separated by guard bands 525, may make up the entire UV spectrum.
Each band may then be separated into a set of subcarriers through
the use of OFDM, which may reduce the impact of multipath in each
band caused by scattering and reflection of UV-C or UV-A.
Application of the Inverse Fast Fourier Transform (IFFT) by the
master WTRU, WTRU1, may be applied in the electrical domain (prior
to optical modulation), and the resulting waveform may be used to
optically modulate a carrier that may be centered at each of the
five UV bands. A different number of UV-C and UV-A bands may be
allocated depending on the UV bandwidth used, or the number of
subcarriers for each of the bands. Devices that support only UV-A
or only UV-C may also be possible.
[0052] FIG. 6 shows the main physical layer stages 600 in a master
WTRU, WTRU1, which may use OFDM and may make use of spectrum
aggregation. In this example, the master WTRU, WTRU1, has been
assigned carriers on only two UV-A wavelengths 610, 615 and only
one UV-C wavelength 605. The number of separate transmit chains in
the transmitter may be as large as the number of total spectral
bands used by the system, depending on how many wavelengths are
allocated to that WTRU. Spectrum from a plurality of bands may be
aggregated using multiple transmit chains wherein each transmit
chain optically modulates a specified wavelength.
[0053] I-Q Mappers 620 receive lists of UV carriers and binary
input streams. The I-Q Mappers output the received information to
an IFFT 630. In the IFFT 630, data from different streams may be
loaded onto the subcarriers assigned to WTRU1 for each UV
wavelength. Subcarriers that are not assigned to a particular WTRU
may be loaded with zero. After the IFFT 630, the information is
transmitted to a pilot/training sequence (P/S) element 640 where
the streams of multiple data elements, received simultaneously, are
converted into a stream of data elements transmitted in time
sequence. A cyclic prefix 650 is then added to the stream. After
the addition of a cyclic prefix 650, each time-domain sequence may
be optically modulated 660 onto the associated UV wavelength and
all wavelengths may be transmitted in parallel. To further increase
the flexibility of the spectrum aggregation method, each UV band
may employ a different configuration of pilot/training sequence
length and placement, fast fourier transform (FFT) size, and cyclic
prefix length. This may ensure that the overall physical layer is
tailored to the differences in optical channel characteristics
between UV-A and UV-C.
[0054] FIG. 7 is a flow diagram of the a channel sounding process
700. If the channel sounding controller in the CC is triggered, the
CC sends a channel sounding request to WTRU1 705. The channel
sounding request may include information such as a specific UV
wavelength and a specific time (T1) for WTRU1 to send a reference
signal. Alternatively, the channel sounding request may be sent to
more than one WTRU, as a broadcast or multicast channel sounding
request. In order to avoid channel sounding collisions, whereby
multiple WTRUs send a reference signal, a random backoff may be
used. The random backoff may occur prior to transmission of the
reference signal. The random backoff may be calculated by each WTRU
or may be signaled via the channel sounding request.
[0055] The CC may send a channel sounding notification to all WTRUs
within range to listen for the reference signal(s) at the specific
UV wavelength(s) and at the specific time(s) (T1) 710. The channel
sounding notification may be sent in the same transmission as the
channel sounding request or may be sent using a separate
transmission. The channel sounding notification may also include
instructions regarding how each WTRU is to respond to the reference
signal. The channel sounding request and/or notification may be
sent using SSRC including but not limited to EHF, Terahertz or
Optical wavelengths or an alternate air interface such as RF.
[0056] WTRU1 may send the reference signal on the specified UV
wavelength at the specified time (T1) 720. The reference signal may
include a field which may be used to identify the transmitting WTRU
(e.g., a subscriber identity, or MAC address). Each WTRU that
detects the reference signal may send a message to the CC, based on
instructions in the channel sounding notification, and/or in
accordance with a predefined procedure 725. The message may include
vicinity and channel condition information for the WTRU 725. The CC
receives this information and may store this information in either
the vicinity database or the capability database 730, based on the
information received. Each device may also include a local database
that may be used to maintain vicinity and channel condition
information.
[0057] FIG. 8 is a flow diagram of a security process 800. WTRU1
(Master) sends a request to the CC to establish a high speed
security link with WTRU2 (Responder), located within the same room
(Room 1) as WTRU1 805.
[0058] WTRU1 may send the request via UV or RF to an AP. The AP
receives the request and may convert the message, if sent via UV,
to transmit it to the CC via an RF link located outside of Room 1
810. The CC receives the request from the AP 815. If the CC is
located within Room 1, WTRU1 may send the request directly to the
CC via a UV or via a RF link.
[0059] The request received by the CC may include capability and
security parameters for WTRU1, including but not limited to data
rate, capability information, channel conditions and applications
associated with WTRU1 815. The request may also include information
regarding the security level for each application associated with
WTRU1. A request to setup a direct link may trigger the channel
sounding controller, as described herein.
[0060] Applications transmitting highly sensitive information may
be assigned a higher quality of security (QoSec) level, while
applications with less sensitive or insensitive information may be
assigned a lower QoSec. The CC may store the parameters and the
application security information in the respective databases (e.g.
either the capability or the security database) 815.
[0061] The CC may send a request to WTRU2 for WTRU2's security and
capability information 820. The CC may send the request either
directly to WTRU2 via UV or via RF, if the CC and WTRU2 are located
in the same room, or via an AP via RF 820. If the request is sent
from the CC to the AP, the AP may convert the RF message to
transmit it to WTRU2 via UV 820, or may transmit the message to
WTRU2 via RF. WTRU2 receives the request and WTRU2 may send
security and capability information either to the AP or to the CC
825. The CC receives this information from either WTRU2 or the AP
and may store the information in the respective database 830.
[0062] The CC may use the information stored in its databases and
the allocation device to allocate subcarriers (i.e., OFDM) within
different wavelengths (i.e., UV-A or UV-C) for each application
associated with WTRU1, so that WTRU1 may establish a high speed
security link with WTRU2. The selection of wavelengths may be a
function of the desired link security. Wavelengths in the UV-C
range may be chosen for services or applications with high QoSec
requirements, while wavelengths in the UV-A range may be chosen for
services or applications with low QoSec requirements.
Alternatively, the wavelength selection may be made to avoid
interference inside a particular room where multiple UV direct
links may be present.
[0063] The number of subcarriers allocated may be a function of the
data rate that is stored. More subcarriers may be assigned for
services requiring higher data rates. Subcarrier allocation may be
based on maximum exposure limits received via the channel sounding
procedure and stored in the capability database. One of several
different waterfilling algorithms may be utilized for this process.
Channel gain to noise ratio (CNR) may be derived through estimates
of the channel response as well as the noise. The noise may take
into account both device noise and environmental noise from the
presence of UV due to sunlight, which may make its way into the
room through windows.
[0064] A constraint equation may be created based on the exposure
limits and the subcarriers assigned to a specified WTRU. The
constraint may be applied to the waterfilling algorithm to obtain
an optimal power for each subcarrier power P.sub.i. If the
specified WTRU is able to achieve the target data rate for the
application without using all of the allocated subcarriers, it may
notify the CC so that these subcarriers are included in the
available subcarrier pool. Periodically (every K seconds), the
waterfilling algorithm may be re-evaluated so that subcarriers may
be assigned.
[0065] The above scheme may be a purely decentralized power
allocation scheme wherein the power allocation decisions may be
made by each WTRU. More accurate results may be obtained using a
centralized allocation scheme, where the constraint equation may be
solved by the CC and power allocation information may then be
transmitted to each WTRU.
[0066] The wavelength and subcarrier allocation may also be made
dependent on channel conditions, which may be based on information
received during the channel sounding process or information
received via parameters.
[0067] The CC may transmit the allocation information to the AP via
an RF link if the CC is located outside of Room 1 835. The AP may
transmit this information to WTRU1 via UV 837. Transmission may
occur over an 802.11 network. If the CC is located within Room 1,
the CC may transmit the allocation information directly to WTRU1
via UV.
[0068] WTRU1 establishes a high speed security link with WTRU2
based on the wavelength and subcarrier information received from
the CC 845. WTRU1 sends a request including parameters for
communication either directly to WTRU2 via UV or to the AP via UV
or via RF 845. If WTRU1 sends the request to the AP, the AP
receives the request and transmits the request to WTRU2 via UV or
via RF 845. WTRU1 may also transmit the request directly to WTRU2
845. If WTRU2 does not support either the wavelengths or
subcarriers allocated by the CC, the wavelengths and subcarriers
may be re-negotiated until both are agreed upon by the WTRU1 and
WTRU2 840. Once the wavelengths and subcarriers are agreed upon,
the direct link communication may begin.
[0069] FIG. 9 is a flow diagram of an encryption process 900.
Symmetric encryption keys may be employed to increase data
throughput in the UV link while maintaining security. Data may be
encrypted and decrypted at the master and responder, WTRU1 and
WTRU2, using a private key shared only by the two WTRUs.
[0070] WTRU1 may send a private key and key transformation
information to WTRU2 using secure wavelengths, such as UV-C 910. To
achieve higher data rates and increase network capacity, less
secure wavelengths such as UV-A or RF may be utilized.
[0071] After exchanging private key information, WTRU1 may send
encrypted data using UV-A 920 wavelengths which may have large
bandwidth capabilities depending on the interference for a given
room or at a given instant of time. WTRU2 receives the information
from WTRU1 and uses the private key to decrypt the information sent
using UV-A 930.
[0072] FIG. 10 shows a UV-enhanced 802.11 protocol stack for a
device that supports two PHY adaptations: RF and UV 1000. The
802.11_UV MAC/PHY protocols may be adaptations of the standard
802.11 protocols. The 802.11_UV MAC 1010 may extend the
capabilities of the standard 802.11 MAC by providing lower-MAC
functions that may be used to interface with the 802.11_UV PHY
layer 1020. The 802.11_UV MAC 1010 may also include capabilities
that support cross-layer optimization of QoS and security
functions, wavelength/subcarrier assignment, and power management.
The 802.11_UV PHY 1020 protocol may be based on an OFDM air
interface. Functionality of the 802.11_UV MAC 1010 may include:
association of devices, resolving QoSec requirements from higher
layers into wavelength and subcarrier assignment, and/or data
multiplexing and recombining in spectrum aggregation.
[0073] The CC may also be applicable to a dynamic spectrum manager
(DSM), a Home NodeB (HNB), a Home enhanced Node B or a Home evolved
Node B (HeNB). The HNB may be a Femto device standardized for
Universal Mobile Telecommunications System (UMTS) and the HeNB may
be a Femto device standardized for Long Term Evolution (LTE).
[0074] Although features and elements are described above with
reference to FIG. 1-10 in particular combinations, each feature or
element can be used alone without the other features and elements
or in various combinations with or without other features and
elements. The sub-elements of the methods or flowcharts described
above with reference to FIG. 1-10 may be realized in any order
(including concurrently), in any combination or sub-combination.
The methods or flow charts described above with reference to FIGS.
1-10 may be implemented in a computer program, software, or
firmware incorporated in a computer-readable storage medium for
execution by a general purpose computer or a processor. Examples of
computer-readable storage mediums include a read only memory (ROM),
a random access memory (RAM), a register, cache memory,
semiconductor memory devices, magnetic media such as internal hard
disks and removable disks, magneto-optical media, and optical media
such as CD-ROM disks, and digital versatile disks (DVDs).
[0075] As used herein, the term "processor" includes, but is not
limited to, a general purpose processor, a special purpose
processor, a conventional processor, a digital signal processor
(DSP), a plurality of microprocessors, one or more microprocessors
in association with a DSP core, a controller, a microcontroller,
one or more Application Specific Integrated Circuits (ASICs), one
or more Field Programmable Gate Array (FPGA) circuits, any other
type of integrated circuit (IC), a system-on-a-chip (SOC), and/or a
state machine.
[0076] A circuit includes any single electronic component of
combination of electronic components, either active and/or passive,
that are coupled together to perform one or more functions. A
circuit may be composed of components such as, for example,
resistors, capacitors, inductors, memory stores, diodes, or
transistors. Examples of circuits include but are not limited to a
microcontroller, a processor, and a transceiver.
[0077] A processor in association with software may be used to
implement a radio frequency transceiver for use in a wireless
transmit receive unit (WTRU), user equipment (UE), terminal, base
station, radio network controller (RNC), or any host computer. The
WTRU may be used in conjunction with modules, implemented in
hardware and/or software, such as a camera, a video camera module,
a videophone, a speakerphone, a vibration device, a speaker, a
microphone, a television transceiver, a hands free headset, a
keyboard, a Bluetooth.RTM. module, a frequency modulated (FM) radio
unit, a liquid crystal display (LCD) display unit, an organic
light-emitting diode (OLED) display unit, a digital music player, a
media player, a video game player module, an Internet browser,
and/or any wireless local area network (WLAN), personal area
network (PAN) or Ultra Wide Band (UWB) module.
* * * * *