WI-LAN Inc. v. Alcatel-Lucent USA Inc. et al

Filing 182

REPLY to 167 Claim Construction Brief,,,,, filed by WI-LAN Inc.. (Attachments: # 1 Affidavit Declaration of Jeffrey T. Han, # 2 Exhibit I - true and correct copy of U.S. Patent No. 5,603,095, # 3 Exhibit II - true and correct copy of U.S. Patent No. 5,239,682, # 4 Exhibit III - true and correct copy of U.S. Patent No. 5,659,598., # 5 Exhibit IV - true and correct copy of WO 96/37054., # 6 Exhibit V - true and correct copy of Sanford Bingham, Multiplexers, Computerworld, Nov. 27, 1989, at 61., # 7 Exhibit VI - true and correct copy of David J. Stang, Network)(Weaver, David)

EXHIBIT IV

peT

WORLD lNTELLEcruAL PROPERTY ORGANIZATION
International Bureau

(pcn

INTERNATIONAL APPLICATION PUBLISHED UNDER mE PATENT COOPERATION TREATY
(51) International Patent Classification 6 :

At

H04B 7126
(21) International Application Number:

(22) International Filing Date:
(30) Priority Data:
952397

WO 96137054

(11) International Publication Number:

(43) International Publication Date:

PCT1FI96/00232

29 April 1996 (29.04.96)

p May 1995 (17.05.95)

FI

(71) Applicant (for all designated States except US): NOKIA
MOBILE PHONES LTD. [FIIFI]; Nakolankatu 8, FIN24100 Salo (FI).

(72) Inventors; and
(75) Inventors/Applicants (for US only): HAMALAINEN, Seppo
[FIIFI]; Lintuvaarantie 21 A 5, FIN-02600 Espoo (FI).
KEURULAINEN, Jere [FIIFI]; Temppelikatu 1 C 22, FIN00100 Helsinki (FI).

21 November 1996 (21.11.96)

(81) Designated States: AL, AM, AT, AU, AZ, BB, BG, BR, BY,

CA, CH, CN, CZ, DE, DK, EE, ES, FI, GB, GE, HU, IS,
W,KE, KG, KP,KR,KZ,LK,LR,LS, LT,LU, LV, MD,
MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD,
SE, SG, SI, SK, TJ; TM, TR, TI, UA, UG, US, UZ, VN,
ARIPO patent (KE, LS, MW, SD, SZ, UG), Eurasian patent·
(AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European patent
(AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU,
MC, NL, PT, SE), OAPI patent (BF, BJ, CF, CG, CI, CM,
GA, GN, ML, MR, NE, SN, TD, TG).
Published
With international search report.
Before the expiration of the time limit for amending the
claims and to be republished in the event of the receipt of
amendments.

(74) Agent: TEKNOPOLIS KOLSTER OY; Oy Kolster Ab, Iso
Roobertinkatu 23, P.O. Box 148, FIN-00121 Helsinki (FI).

(54) Title: A METHOD FOR ESTIMATING THE QUALITY OF A CONNECTION, AND A RECEIVER
(57) Abstract
The present invention relates to a
method for estimating the quality of a connection in a cellular radio system, and a re"
ceiver (14) of a cellular radio system, com"
prising comparison means (23) for estimating by means of the received pilot signals
(26) and the reveived combined broadband
signal (28) the interference caused by the
base stations (10-13) at the terminal equipment (14). The method may be utilized
e.g. for distributing the traffic load of the
base stations and in interference cancellation methods.

r --------I

21

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I

24

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29
, .1

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I

251

30

--?

FOR THE PURPOSES OF INFORMATION ONLY
Codes used to identify States party to the PCI' on the front pages of pamphlets publishing international
applications under the PCI'.
AM
AT
AU
BB
BE
BF
BG
BJ
BR
BY
CA
CF
CG
CH
CI
CM
CN
CS
CZ
DE
DK
EE
ES
FI

FR
GA

Annenia
Austria
Australia
Barbados
Belgium
Burkina Paso
Bulgaria
Benin
Brazil
Belarus
Canada
Central African Republic
Congo
Switzerland
COte d'Ivoire
Cameroon
China
Czechoslovakia
Czech Republic
Gennany
Denmark
Estonia
Spain
Finland
France
Gabon

GB
GE
GN
GR
HU

IE
IT

JP
KE

KG
KP

KR
KZ

Ll
LK
LR
LT
LV

LV
Me
MD
MG
ML
MN
MR

United Kingdom
Georgia
Guinea
Greece
Hungru:y
Ireland
Italy
Japan
Kenya
Kyrgystan
Democratic People' 5 Republic
of Korea
Republic of Korea
Kazakhstan
Liechtenstein
Sri Lanka
Liberia
Lithuania
Luxembourg
Latvia
Monaco
Republic of Moldova
Madagascar
Mali
Mongolia
Mauritania

MW
MX
NE
NL
NO
NZ
PL

PT
RO
RU
SD
SE
SG
SI
SK
SN
SZ
TD

TG
TJ
TT

UA
UG
US
UZ
VN

Malawi
Mexico
Niger
Netherlands
Norway
New Zealand
Poland
Portugal
Romania
Russian Federation
Sudan
Sweden
Singapore
Slovenia
Slovakia
Senegal
Swaziland
Chad
Togo
Tajikistan
Trinidad and Tobago
Ukraine
Uganda
United States of America
Uzbekistan
Viet Nam

,)

,.

PCTIFI96/00232

W096/37054

1

A method for estimating the quality of a connection,
and a receiver

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The present invention relates to a method for
estimating the quality of a connection in a receiver of
a: subscriber terminal equipment in a cellular radio
system when each base station is transmitting a pilot
signal in the cellular radio system.
The invention further relates to a receiver of .
a cellular radio system.
In a cellular radio system, the quality of the
connection between a base station and a subscriber
terminal equipment varies constantly. This variation is
due to interference factors occurring on the radio
path, as well as attenuation of radio waves as a
function of distance. Interference is also caused at
the receiver of the terminal equipment by those signals
that arrive from other base stations in the coverage
area, serving other terminal equipments.
In a CDMA method, the narrow-band data signal
of the user is modulated by a spreading code having a
remarkably broader band than the data signal to a
relatively broad band. In the known experimental
systems, bandwidths of 1.25 MHz, 10 MHz, and 50 MHz,
for instance, have been used. The spreading code
usually consists of a long pseudorandom bit sequence.
The bit rate of the spreading code is much higher than
that of a data signal, and to make a distinction
between the spreading code and data bits and symbols,
the bits of the spreading code are termed as chips.
Each data symbol of the user is multiplied by all chips
of the spreading code. Thus, the narrow-band data
signal spreads onto the frequency band used by the
spreading code. Each user has an individual spreading
code. Several users transit simultaneously on the same

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PCTIFI96/00232

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frequency band, and data signals'are distinguished from
each' other in the receivers on the basis of a
pseudorandom spreading code. An example of CDMA is a
cellular radio standard EIA/TIA IS-9S.
A receiver is preliminary synchronized with
,the received signal by means of a pilot signal sent by
the base station, and thereafter, correlators located
in the receivers are synchronized with a desired
signal, which they identify on the basis of the'
spreading code. The correlators return the data signal
onto the original narrow frequency band. In an ideal
case, the signals arriving at the receiver, which
signals have been multiplied by another spreading code,
do not correlate in the receiver, but maintain their
broad band. An attempt is made to choose the spreading
codes employed by the system so that they do not
correlate with each other, that is, they are mutually
orthogonal.
It
is
typical
of
a
cellular network
environment that the signal travelling between the user
and the base station does not propagate straight, but,
depending on the features of the environment, .along
several
routes
of different
lengths
from
the
transmitter to the receiver. This multipath propagation
takes place although there would be a straight visual
contact between a base station and a mobile station.
Multipath propagation is mainly due to reflections of
the signal from the surrounding surfaces. Signals
travelling different routes have different delays in
the propagation time, and they thus arrive at the
receiver in different phases.
Generally speaking, ~he spreading codes are
not
orthogonal
at
all
possible
error values.
Therefore, signals delayed in different ways cause
interference in the detection of other signals. The

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users thus interfere with each other, and this
interference is termed as multiuser interference. CDMA
is an interference limited system. When the number of
users, and thus also the effect of the multiuser
interference increases, the signal-to-interference
xatio of the connections becomes poorer. At a certain
number of users, the signal-to-interference ratio
increases so high that maintaining the connection is
complicated, and the number of users cannot be'
increased without risking the quality of the existing
connections. Typically, on one radio channel having a
bandwidth of 1.25 MHz, for instance, there may be up to
30 - 40 simultaneous CDMA connections. If more channel
capacity is needed ·e.g. at the base station, it
requires taking a new radio channel into use.
In a cellular radio environment, the users are
located randomly with respect to the base station and
to each other. Attenuation of the signal between the
base station and the terminal equipment is described by
means of attenuation with communication distance, which
increases at least quadratically as the distance
increases. For this reason, terminal equipments located
near the base station may cover the transmission of the
stations located more remote especially if the power
control of the terminal equipments is not accurate,
since even a small correlation of a strong signal may
cause a major interference in the detection of a weak
signal. This phenomenon is termed as a near-far
problem. The aim of the power control of ,the terminal
equipments is to enable the same power level to be
received at the base station from all the terminal
equipments, regardless of the distance of the terminal
equipment from the base station. It is difficult to
implement accurate power control, however, e.g. due to'
the rapidly changing nature of the radio channel.

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Mul tiuser interference of CDMA systems has
also been reduced by means of various prior art
multiuser interference cancellation methods
(IC,
Interference Cancellation), and multiuser detection
(MUD) ," This methods are best suited for reducing
interference originating from the user's own cell, and
thus for increasing the capacity of the system. These
methods, however, do not provide improvement in the
size of the area covered by the base station, in other
words, the size of the cell remains unchanged when
these methods are employed,
A so-called RAKE receiver if generally used as
a CDMA receiver, comprising one or more RAKE branches.
Each branch is an independent receiver unit whose task
it is to combine and demodulate one received signal
component, Each RAKE branch can be commanded to be
synchronized with a signal component that has travelled
along its individual route, and .in a conventional CDMA
receiver, the signals of the receiver branches are
advantageously combined, which provides a high-quality
signal.
.In a CDMA cellular radio system, a pilot
signal maybe used e.~, in the following manner. In a
preferred embodiment of the invention, each base
station transmits a pilot signal, which is usually a
part of a pseudorandom spreading code. The subscriber
terminal equipment uses said pilot signal
for
synchronization of the reception, as well as for
preliminary time, frequency and phase identification of
the base station. The subscriber terminal equipment
receives the pilot signal continuously. All the base
stations transmit a pilot signal that has been encoded
in the same way, but the phase offsets of the spr~ading
codes of the signals differ from each other , which
enables distinguishing the signals, and thus the base

"

..
""

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stations from each other. As the codes of the pilot
signals are similar, the subscriber terminal equipment
will find the time synchronization of the system at. one
time when it goes through all the code phases. In
accordance with a prior art technique, the strongest
signal found corresponds to the code phase of the best
base station.
In a normal case, the subscriber terminal
equipment does not take into account the interference
caused by the base stations regarding each base station
individually. In that case, the unbalance in the
traffic load between the base stations may be taken
into account in some elements of the network only. If
it is desirable that the subscriber terminal equipment
should 'be aware of the interference levels caused by
the different base stations, the subscriber terminal
equipment must be transmitted the information on the
traffic load of the base station along the signalling
channel.
The obj ect .of the present invention is to
estimate the interferences caused by the base stations
at the subscriber terminal equipment, to determine the
mutual relations of the interferences, and thus to
reduce the interferences.
This is achieved with a method of the type
described in the introduction, which method is
characterized in that the interference caused by one or
more base stations is estimated by comparing the pilot
signals sent by said base stations with a combined
broadband signal.
The receiver of the invention is characterized
by comprising comparison means for estimating by means
of pilot signals received from said base stations, and
the received combined broadband signal the interference
caused by one or more base stations at the terminal

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equipment.
The basic idea of the method of the invention
is to calculate by means of the pilot signals, without
separate signalling, the signal strength transmitted by
one base station in proportion to all other signals
arriving at the receiver, and to use the information
thus obtained for improving the quality of the
connection.
The method of the invention several advantages .
provides several advantages and solutions to a number
of problems. When choosing the base stations, for
example, it is advantageous to know the mutual
correlations of the base stations regarding the traffic
load. If the uneven traffic load of the network is not
taken into account, a connection may be established to
a base station which is already operating at the upper
limit
of
its
capaci ty.
Furthermore;
reason.able
allocation of the terminal equipments between the base
stations will level out the traffic load of the
network, and increase the capacity of the network.
In interference cancellation algorithms (e.g.
Ie), it is naturally advantageous to make an attempt to
eliminate the most significant interferences. It is
thus advantageous to find out from which base station
the major interferences originate. It is more difficult
and slower to find an interfering signal as compared
with the method of the invention when the MUD algorithm
does not know the source of a strong interference.
The
solution of the
invention enables
estimating the interference level caused by each base
station in proportion to other base stations from the
subscriber terminal equipment.
It
also
enables
estimating mutual traffic loads of the base stations.
Since the present cellular radio systems do
not aeparately take the interference of the base

PCTIFI96/00232

W096/37054

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stations into account, the uneven traffic load of the
network and the base stations is thus not considered
either. In the solution in accordance with. the
invention, the correlations related to the traffic load
between the base stations are known by the subscriber
terminal equipment, and the RAKE element may thus be
allocated better than heretofore, thus improving the
performance of the network.
If information on the traffic load of the cell'
or on the total transmission power is transmitted from
all the base stations that are being studied, it
requires a remarkable amount of additional signalling,
which is a significant drawback compared with the
solution of the invention.
In the following, the invention will be
described with reference to the examples in the
attached drawings, in which
Figure 1 shows the parts of a CDMA cellular
radio system which are essential to the invention,
Figure 2 is a block diagram illus-trating the
structure of the receiver of the invention.
The method of the invention may be used in a
CDMA system transmitting a pilot signal. Figure 1 shows
an example of a CDMA cellular radio system in which it
is assumed that the actual data transmission. takes
place between a base station 10 and a subscriber
terminal equipment 14. Base stations 11, 12, and 13 are
interfering with the transmission. Since the base
stations are ·located within different distances from
the subscriber terminal equipment, and behind different
natural obstacles, buildings, etc., the interfering
effects of their transmissions are different in
strength. In a situation as shown in Figure 1, the
interfering effect of base station 13 is the strongest,
as it is located near a terminal equipment. Base

PCTIFI96/00232

W096/37054

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station 11 is located relatively far away, and the
interference caused by it is thus only moderate,
whereas the interference caused by base station 12 is
minor since it is located far away and behind a natural
obstacle 15. When the subscriber terminal equipment
moves, the situation changes constantly.
In the solution in accordance with the
invention, the terminal equipment receives the pilot
signal of the base station listened, and obtains from
it the preliminary information for receiving the 'actual
data signal. At the terminal equipment, the pilot
signal sent by each base station is measured, and in an
advantageous embodiment f said signal is compared by
means of correlation wi th a received combined broadband signal. Said comparison is most advantageously
carried out parallel, that is, simultaneously for
several pilot signals. The comparison may also be
carried out in series, i.e. in one comparison, only one
pilot signal at a time is compared with the combined
broadband signal. The correlation result may be
calculated e.g. on the basis of iormula(l) for each
base station:

(1 )

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in which Pi represents the pilot signal received from
the ith base station, T is the measurement period, and
I is the received combined broadband signal. The
subscript i indicates the number with which a reference
is made to each base station separately. Mathematical
operations, such as removing the average, variance
normalization, interpolation,decimation, filtering,

W096/37054

PCTIFI96/00232

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etc. may be carried out for the measurement results
prior to calculating the correlation. The correlation
result may be proportioned to the distance of . the
transmitter and the receiver, and other factors having
an effect on the connection by t~king the attenuation
with communication distance into account, herein marked
with c i • Thus, the attenuation with communication ,.
distance c i is also the weighting coefficient of the ph
base station.
The weighting coefficient c i may
advantageously also be shown in form of a formula 2:
~ransmi t:t:ed

p
l

p7eceived
l

15

20

(2)

in which the information on the transmission power is
known from before. A weighted correlation Ki can now be
calculated as a product of the correlation 81 and the
weighting coefficient c i , i.e. Ki = 8i x c i • The
weighting coefficient may also be disregarded, in which
case the value of the weighting coefficient c i is one;
The parameters Qi for weighting the interferences caused
by the different base stations are advantageously
obtained by means of a formula 3:
K·
Q.= ___
l
l

25

N

LKn
n=l

(3)

in which N represents the number of the base stations,
representing one or mor.e of all the basestatioIis
received by the terminal equipment. In other words, the
parameter Qi of one base station is the proportion of
the weighted correlation coefficient Ki of said base

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station to the sum of the weighted correlation
coefficients of all the base stations included in the
measurements.
The receiver illustrated in Figure 2 showing
one possible embodiment of the invention comprises
means for making a comparison between the combined
broadband signal and the pilot signals received from
different base stations. The receiver comprises a radio
frequency element 20, a detector unit 21, a signal
strength measuring element 22, a load estimating unit
23, in which attenuation with communication distance is
also taken into account in a preferred embodiment of
the invention, and a control unit 24. Block 21
comprises RAKE branches 215a - 215d and a block 216,
which comprises e.g. diversity combiner, interference
cancellation means,
power estimating means,
and
decoding means. A signal received in the radio
frequency element 20 is converted from the carrier
frequency into a broadband signal 27 containing data.
Thereafter, the signal 27 enters the detector unit 21,
which measures the strength of the pilot signal,
combines the signals received from the RAKE branches
advantageously, and decodes the signal. In this
example, four correlator branches 215a - 215d operate
as RAKE elements, being able to operate as searchers or
receiver branches. The signal 27 also branches after
the radio frequency element 20 into the signal strength
measuring element 22, in which the strength of the
combined broadband signal 27 is measured. In the load
estimating unit 23, at which both the combined
btoadband signal 28 and the pilot signal 26 arrive, the
effect of the interference caused by various base
stations in proportion to the combined broadband signal
is estimated with the method of the invention. When the
strengths of the pilot signals of the base stations

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measured in the detector unit 21 are also taken into
account in a preferred embodiment of the invention, the
relative interference levels of the base stations .may
be determined, that is, a parameter Qi is obtained
describing the interference level of the each base
station individually. Said parameter may be calculated
e.g. with formula 3. The control unit 24 controls the
receiver on the basis of a signal 30, that is, on the
basis of the bits of the user and a signal 29 coming
from the load estimating unit 23. The load estimating
unit 23 thus has an effect on handover algorithms of
the control unit 24,
interference cancellation,
allocation of RAKE elements, power control, and MUD
control. The control signals of the receiver going out
from the control unit 24 are marked with arrows 25. The
control unit 24 controls the detector unit 21, among
other things. The invention thus relates to block 23 of
Figure 2, that is, the load estimating unit. The load
estimating unit provides an estimate of the relative
interference levels of the base stations by means of
the method of the invention. This estimate may be
utilized in the control unit 24 controlling the
operation of the receiver. Although various means may
be utilized to implement the present inventive method,
a .VLSI or an ASK circuit based on digital signal
processing is utilized in the preferred embodiment of
the invention due to its simplicity of operation and
construction.
When the terminal equipment is aware of the
relative interference levels Qi of the base stations,
this piece of information may be utilized e. g. in a
handover algorithm, allocation of MUD, allocation of
RAKE elements, etc. The method does not increase the
amount of signalling, but it makes the terminal
equipment more independent, and less dependent on the

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control received from the network.
Although the invention has been disclosed
above with reference to the example in accordance with
the attached drawings, it is obvious that the invention
is not limited thereto, but it may be modified in a
number of ways within the inventive idea disclosed in
the attached claims.

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13
Claims:

•

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1. The present invention relates to a method
for estimating the quality of a connection in a
receiver o"f a subscriber terminal equipment (14) in a
Gellular radio system when each base station (10 13)is transmitting a pilot signal, c h a r a c t e r i zed in that the interference caused by one or more
base stations (10 - 13) is estimated by comparing the
pilot signals transmitted by said base stations (10 13) with a .combined broadband signal.
2. A method as claimed in claim 1,
c h a r a c t e r i zed in that the comparison of
two or more received pilot signals (26) and the
combined broadband signal (28) is carried out parallel
so
that
several
comparisons
are
going
on
simultaneously.
3. A method as claimed in claim 1,
c h a r a c t e r i zed in that the comparison of
the' received pilot signals (26) and the combined
broadband signal (28) is carried out in series 'so that
the comparisons are made consecutively one at a time.
4. A method as claimed in claim 1,
c h a r a c t e r i z e d in that the comparison of
the received pilot signals (26) and the combined' ,
broadband signal (28) is carried out by calculating the
correlation between said signals.
5. A method as claimed in claim 1,
c h a r a c t e r i zed in that the attenuation with
communication distance between the base station (10 13) and the receiver (14) is also taken into account in
the estimation of the interference levels of the base
stations.
6. A method as claimed in claim 5,
c h a r a c t e r i zed in that-the attenuation with

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communication distance is calculated on the basis of
the transmission power of the pilot signal of the base
station (10 - 13) and the power of the pilot signal
(26) received by t·he terminal equipment (14).
7. A method as claimed in claim 1,
c h a r a c t e r i zed in that only one received
pilot signal (26) at a time. is compared with the
combined broadband signal (28) in. one comparison.
8. A method as claimed in claim 7,
c h a r a c t e r i zed· in that the relative
interference levels of the base stations (10 - 13) are
obtained in form of the proportion of the interference
level of the individual base stations and the total
interference level when the total interference level is
the sum of individual interference levels.
9. A method as claimed in claim 1 or 8, c h a
r a c t er i zed in that the estimating results of
the interference levels of the base stations (10' - 13)
are utilized when choosing the base station (10 - 13)
to communicate with.
10. A method as claimed in claim 1 or 8, c h
a r a c t e r i zed in that the estimating results
of the interference levels of the base stations (10 13) are utilized in interference cancellation methods.
11. A receiver (14) of a cellular radio
system, ch a r a c t e r i z e d
by comprising
comparison means (23) for estimating by means of pilot
signals (26) received from said base stations (10 13), and the received combined broadband signal (28)
the interference .caused by one or more base stations
(10 - 13) at the terminal equipment (14).
12. A receiver (14) as claimed in claim 11, c
h a r a c t e r i z .e d by comprising means (23) for
making a comparison as a correlation between the pilot
signal (26) received from the base station and the

•

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combined broadband signal (28).'
13. A rec~iver (14) as claimed in claim 11, c
h a r a c t e r i zed by comprising means (23). for
. taking into accoun't the attenuation with communication
distance in estimating the interference.
14. A receiver (14) as claimed in claim 13, c
h a r a c t e r i zed by comprising means (21) for
calculating the attenuation with communication distance
on the basis of the transmission power of the pilot .
signal of the base station and the power of the pilot
signal (26) received by the terminal equipment.
15. A receiver (14) as claimed in claim 11, c
h a r a c t e r i zed by comprising means (23) for
calculating relative interference levels of the base
stations.
16. A receiver (14) as claimed in claim 15, c
h a r a c t e r i ze d by comprising means (21) for
choosing the base station to communicate with.
17. A receiver (14) as claimed in claim 15, c
h a r a c t e r i zed by comprising interference
cancellation means (21).

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1/1

X

X

ftEJ

11

EJ

•

12

;,

15

13

Fig. 1
STS

-,--

-I

1
1
216
1
1
1
1
251

24

30

I

C

_J

0

-/

"

?

n

•
•

•
r
0

29

Fig. 2

1
INTERNATIONAL SEARCH REPORT

International application No.

PCT/FI 96/00232
A. CLASSIFICATION OF SUBJECT MATTER

IPC6: H04B 7/26

According to International Patent Classification (IPC) or to both national classification and IPC
B. FIELDS SEARCHED
Minimum documentation searched (classification system followed by classification symbols)

IPC6: H04Q, H04B
Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched

SE,DK,FI,NO

cla~ses

as above

Electronic data base consulted during the .international search (name of data base and, where practicable, search terms used)

C. DOCUMENTS CONSIDERED TO BE RELEVANT
Category· atation of document, with indication, where appropriate, of the relevant passages

P,A

WO 9524086 A2 (PHILIPS ELECTRONICS N.V.),
8 Sept 1995 (08.09.95), page 3, line 19 - page 5,
line 7

Relevant to claim No.

1-17

-P,A

EP 0661830 A2 (NEe CORPORATION), 5 July 1995
(05.07.95), page 2, line 39 - line 42

1-17

-A

US 5099493 A (A.E. ZEGER ET AL), 24 March 1992
(24.03.92), column 2, line 14 - line 18; column 2,
line 34 - line 49

1';"17

--

[]
•
"A"
"EN
"LN
·0'

"P'

Further documents are listed in the continuation of Box C.
Special categories of cited documents:
document defining the general Slate of the art which is not considered
to be of particular relevance
erlier document but published on or after the international filing date
document which may throw doubts on priority c1aim(s) or which is
cited to eSlablish the publication date of another citation or other
lipecial rea.~on (as specified)
document referring to an oral disclONre. use, exhibition or other
means
document published prior to the international filing date but later than
the priority date cl.aimed

Date of the actual completion of the international search

[iJ

See patent family annex.

.,.N later document published after the international filing date or priority
date and not in conflict with the application but. cited to understand
the principle or theory underlying the invention
"X" document of particular relevance: the claimed invention cannot be
considered novel or cannot be considered to involve an inventive
Slep when the document is taken alone
'y' document of particular relevance: the claimed invention cannot be
considered to involve an inventive step when the document is
combined with one or more other such documenl~. such combination
being obvious to a person skilled in the art
'&" document member of the same patent family

Date of mailing of the international search report

25 -09- 1998

20 Sent 1996
Name and mailing address of the ISA;

Swedish Patent Office
Box 5055. S-102 42 STOCKHOLM
Facsimile No. + 46 8 666 02 86
Form PCf IISA/21 0 (second sheet) (July 1992)

Authorized officer

Marcus Wik
Telephone No.

+ 46 8 782 25 00

2.
INTERNATIONAL SEARCH· REPORT

International application No.

PCT/FI 96100232
C (Continuation). DOCUMENTS CONSIDERED TO.BE RELEVANT
Category * Citation of document, with indication, where appropriate, of the relevant passages

A

EP 0564937 Al (ROKE MANOR RESEARCH LIMITED),
13 October 1993 (13.10.93), column 1,
line 46 - column 2, line 16

Relevant to claim No.

1-17

..E,A

EP 0721264 Al (NTT MOBILE COMMUNICATIONS NETWORK
INC.), 10 July 1996 (10.07.96), page 1,
line 16 - line 22, abstract

•
.1-17

-A

EP 0641102 A2 (PHILIPS ELECTRONICS UK LIMITED),
1 March 1995 (01.03.95), page 3,
column 17 - page 4, line 12

1-17

-A

US 5416797 A (K.S. GILHOUSEN ET AL), 16 May 1995
(16.05.95), column 4, line 23 - line 27

1-17

-E,A

US 5548613 A (T. KAKU ET AL), 20 August 1996
(20.08.96), column 1, line 27 - line 29; .co1umn 1,
line 36 - line 39

--

--------

Form PCT/ISA/210 (continuation of second sheet) (July 1992)

1-17

INTERNATIONAL SEARCH REPORT
International application No.
Information on patent family members
Patent document
cited in search report

I

05/09/96

Publication
date

PCT/FI 96/00232

Patent family
member(s)

I

Publication
date

WO-A2-

08/09/95

EP-A2-

..

9524086

EP-A-

0661830

05/07/95

AU-ACA-AJP-A-

US-A-

5099493

24/03/92

NONE

EP-A1-

0564937

13/10/93

CA-AGB-A,B-

2093566
2268371

11/10/93
05/01/94

EP-A1-

0721264

10/07/96

WO-A-

9600470

04/01/96

EP-A2-

0641102

01/03/95

JP-A-

7177124

14/07/95

US-A-

5416797

16/05/95

AU-BAU-ABG-ACA-ACN-AEP-AHU-AHU-DIL-AJP-TSK-AUS-AUS-AUS-AUS-AUS-AWO-A-

652956
8401691
97222
2085890
1061312
0536334
64657
9204111
98598
6501349
387192
5103459
5309474
5504773
5511073
5535239
9200639

15/09/94
23/01/92
27/05/94
26/12/91
20/05/92
14/04/93
28/01/94
00/00/00
27/02/94
10/02/94
10/08/94
07/04/92
03/05/94
02/04/96
23/04/96
09/07/96
09/01/92

AU-ACA-AEP-AJP-A-

8176094
2139269
0661829
7202756

06/07/95
01/07/95
05/07/95
04/08/95

0696398

14/02/96

8182894
2139268
7202843

06/07/95
01/07/95
04/08/95

------------------------------------------------------------------------US-A-

5548613

20/08/96

-------------------------------------------------------------------------

Form PCf/ISA/21O (patent famIly annex) (July 1992)