EON Corp. IP Holdings, LLC v. Apple Inc.

Filing 1

COMPLAINT against Apple Inc. ( Filing fee $ 350 receipt number 0540-3922929.), filed by EON Corp. IP Holdings, LLC. (Attachments: # 1 Exhibit A - '757 Patent, # 2 Exhibit B - '101 Patent, # 3 Exhibit C - '546 Patent, # 4 Exhibit D - '491 Patent, # 5 Civil Cover Sheet)(Scardino, Daniel)

EXHIBIT D

111111111111111111111111111111111111111111111111111111111111111111111111111
US005592491A

United States Patent

[19]

Dinkins

[45]

[54]

WIRELESS MODEM

[75]

Inventor:

[73]

Appl. No.: 348,618

[22]

Filed:

Primary Examiner-Douglas W. Olms
Assistant Examiner-Dang Ton
Attorney, Agent, or Firm-Cushman Darby & Cushman IP
Grop of Pillsbury Madison & Sutro, LLP

Assignee: EON Corporation, Reston, Va.

[21]

5,592,491
Jan.7, 1997

Patent Number:
Date of Patent:

[11]

Gilbert M. Dinkins, Herndon, Va.

[57]
Dec. 2, 1994
Related U.S. Application Data
[63]

Continuation-in-part of Ser. No. 966,414, Oct. 26, 1992, Pat.
No. 5,388,101.

[51]
[52]
[58]

Int. Cl. 6

••••••.•••.••••••.•.•••••..•.••.••••••••.••••••••••••••• H04J 3/16
U.S. Cl•............................ 370/277; 455/ll.l; 379/59
Field of Search .................................. 370/95.1, 95.2,
370/95.3, 60, 60.1, 94.1, 94.2, 75, 32, 97;
455/34.1, 34.2, 57.1, 58.2, 56.1, 50.1, 51.1,
54.1, 33.1, 33.2, 33.3, 11.1, 13.1, 13.2,
13.3, 13.4, 15, 16; 3751211, 222; 379/4

[56]

References Cited
U.S. PATENT DOCUMENTS
5,282,204
5,494,698

ABSTRACT

A system and method for communicating between local
subscriber units and a local base station repeater cell in a
two-way communication interactive video network. In one
embodiment, a modem is used to enable communications
between a subscriber unit and a local base station repeater
cell when the subscriber units are unable to receive rf
transmissions from the local base station repeater cell. The
local base station repeater cell is connected via a telephone
line to the modem. Data communications are sent from the
local base station repeater cell to the modem. The modem is
also connected via and rf link to the subscriber unit. The
modem then transmits the data communications received
from the local base station repeater cell to the subscriber
unit. Responses from the subscriber unit are then transmitted
over the rf link from the subscriber unit to the modem. The
modem then transmits the responses over the telephone line
to the local base station repeater cell.

1/1994 Shpancer et al. ...................... 370/95.1
811995 Kito ....................................... 370/95.1

23 Claims, 3 Drawing Sheets

16
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SWITCHING MEANS
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22

MODEM __)

U.S. Patent

Jan. 7, 1997

Sheet 1 of 3

5,592,491

FIG. 1(Prior Art)

16
LOCAL
REMOTE
20
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RECEIVER 1 - - - - L - - - J - . 1 STATION
REPEATER
CELL

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Tx
SUBSCRIBER UNIT

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U.S. Patent

5,592,491

Sheet 2 of 3

Jan.7, 1997

FIG. 2

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SUBSCRIBER UNIT
SWITCHING MEANS
• PATHA .....-13

•••

PATH B

MODEM

22

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U.S. Patent

Jan.7, 1997

5,592,491

Sheet 3 of 3

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from receiving signals from the local base station repeater
cell.
This is a continuation-in-part of a application Ser. No.
Thus, the need has arisen for a system to enable commu07/966,414, filed Oct. 26, 1992, by G. Dinkins, entitled
nications between a subscriber unit and a local base station
"Interactive Nationwide Data Service Communication Sys- 5 repeater cell in areas where such communication has previtern For Stationary And Mobile Battery Operated Subscriber
ously been impaired, which does not require the addition of
Units", which issued as U.S. Pat. No. 5,388,101.
numerous costly local station repeater cells, which is not
dependent on the physical location of the subscriber unit,
and which does not significantly increase the cost of comTECHNICAL FIELD
10 munication within the interactive two-way broadcast data
This invention relates to an interactive two-way data
service network.
service network, and more particularly, to communication
within an interactive two-way broadcast data service netDISCLOSURE OF THE INVENTION
work.
It is therefore an object of the present invention to provide
15
a system to enable communications between a subscriber
BACKGROUND ART
unit and a local base station repeater cell in areas where such
Communication within an interactive two-way broadcast
communication has previously been impaired, which does
data service network is described in detail in application Ser.
not require the addition of numerous costly local station
No. 07/966,414, filed Oct. 26, 1992 now U.S. Pat. No. 20 repeater cells, which is not dependent on the physical
5,388,101 G. Dinkins, entitled "Interactive Nationwide Data
location of the subscriber unit, and which does not signifiService Communication System For Stationary And Mobile
cantly increase the cost of communication within the interBattery Operated Subscriber Units" which is incorporated
active two-way broadcast data service network. The above
herein by reference. In such a system, a local base station
object has been achieved using a modem which is used to
repeater cell comprises a central transmitter and data pro- 25 enable communications between a subscriber unit and a
local base station repeater cell when the subscriber units are
cessing site for transmitting digital data to individual lowunable to receive rftransmissions from the local base station
cost, portable, battery-operated, milliwatt transmitter, subscriber units within a local base station designated area. A
repeater cell. The local base station repeater cell is conplurality of receive only stations, remote receivers, are
nected via a telephone line to the modem. Data communidistributed throughout the local base station designated area 30 cations are sent from the local base station repeater cell to
the modem. The modem is also connected via an rf link to
and are connected by wire, cable, microwave link, or radio
the subscriber unit. The modem then transmits the data
to the local base station repeater cell. The remote receivers
communications received from the local base station
process and relay transmitted digital data received from the
repeater cell to the subscriber unit. Responses from the
individual subscriber units. Thus, the local base station
repeater cell transmits data directly to the individual sub- 35 subscriber unit are then transmitted over the rf link from the
subscriber unit to the modem. The modem then transmits the
scriber units. The milliwatt transmitter individual subscriber
responses over the telephone line to the local base station
units, however, do not transmit data directly back to the local
repeater cell. In so doing, two-way communications in an
base station repeater cell. Instead, the individual subscriber
interactive broadcast network are achieved even in condiunits transmit to a remote receiver which then relays the data
to the local base station repeater cell. The use or remote 40 tions which have previously prevented such communications.
receivers allows the individual subscriber units to transmit
data using power in the milliwatt range.
BRIEF DESCRIPTION OF THE DRAWINGS
Unfortunately, under certain conditions, individual subscriber units are unable to receive transmissions from the
The accompanying drawings, which are incorporated in
local base station repeater cell. For example, a user may 45 and form a part of this specification, illustrate embodiments
purchase a subscriber unit and place the subscriber unit in an
of the invention and, together with the description, serve to
area which is not yet equipped with or is not covered by a
explain the principles of the invention:
local base station repeater cell. Additionally, a subscriber
FIG. 1 shows a Prior Art interactive broadcast system
unit may be located within range of a local base station
wherein a local base station repeater cell transmits data
repeater cell, but may be positioned, for example, in a 50 directly to a subscriber unit.
basement or other physical location which prevents the
FIG. 2 shows a communication system in an interactive
subscriber unit from receiving transmissions from the local
broadcast system wherein a modem enables communication
base station repeater cell.
between a local base station repeater cell and a subscriber
In an attempt to alleviate reception problems, local base
unit over one of two separate paths in accordance with the
station repeater cells have been situated with overlapping 55 present invention.
coverage to produce strong signals throughout a given area.
FIG. 3 shows another embodiment of a communication
However, such placement of local base station repeater cells
system in an interactive broadcast system wherein a modem
is extremely costly due to the number of local base station
enables communication between a subscriber unit and a
repeater cells required, and such "crowded" placement of the
local base station repeater cells is not always practical. In a 60 network hub switching center in accordance with the present
invention.
further attempt to deal with ineffective communication
WIRELESS MODEM

between the local base station repeater cell and the subscriber unit, the location of the user is determined at the time
of sale of the subscriber unit to the user. However, even if the
user's location is within an area covered by the local base
station repeater cell, the subscriber unit might still be placed
in a physical location which prevents the subscriber unit

BEST MODE FOR CARRYING OuT THE
INVENTION
65

Reference will now be made in detail to the preferred
embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention

5,592,491

3

4

other frequencies such as, for example, 902 MHz or 45
will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to
MHz. Subscriber unit 12 then responds to messages and
limit the invention to these embodiments. On the contrary,
transmits data messages to local base station repeater cell10
the invention is intended to cover alternatives, modifications
via modem 22. That is, subscriber unit 12 sends a data
and equivalents, which may be included within the spirit and 5 message or response over rf link 26 to modem 22. Modem
scope of the invention as defined by the appended claims.
22 then relays that message or response over link 24 back to
local base station repeater cell 10. Thus, two-way commuWith reference now to Prior Art FIG. 1, an interactive
nication between local base station repeater cell 10 and
broadcast network as set forth in application Ser. No.
subscriber unit 12 is achieved.
07/966,414, filed Oct. 26, 1992, now U.S. Pat. No. 5,388,
101 by G. Dinkins, entitled "Interactive Nationwide Data 10
With reference still to FIG. 2, in the present embodiment,
Service Communication System For Stationary And Mobile
when communicating over Path B, modem 22 is connected
Battery Operated Subscriber Units" is schematically shown.
to local base station repeater cell 10 through telephone line
As shown in Prior Art FIG. 1, a local base station repeater
24 using, for example, either an 800 or 900 telephone
cell 10 communicates with a subscriber unit 12 over an rf
number. Next, TV listings, for example are downloaded into
link 14 of, for example 218-219 MHz. Subscriber unit 12
modem 22 and into subscriber unit 12. The telephone link
15
transmits data back to local base station repeater cell10 via
between subscriber unit 22 and local base station repeater
a remote receiver 16. That is, subscriber unit 12 transmits
cell 10 via modem 22 is broken after approximately 30
messages directly to remote receiver 16 over an rf link 18.
seconds allowing for normal use of the telephone line. Use
Remote receiver 16 then transfers the messages received
of the link between subscriber unit 22 and local base station
from subscriber unit 12 to local base station repeater cell10
repeater cell 10 via modem 22 is protected by a serial
20
over, for example, hard wire link 20.
number handshake. Initiation of auto dial-up on a daily or
more frequent schedule by subscriber unit 12 insures that the
With reference still to Prior Art FIG. 1, under certain
data received by subscriber unit 12 remains current.
conditions, subscriber unit 12 is unable to receive transmissions via rf link 14 from local base station repeater cell10.
Referring still to FIG. 2, the present invention provides
For example, subscriber unit 12 may be placed in an area 25 for two-way communication between local base station
which is not yet equipped with or is not covered by a local
repeater cell10 and subscriber unit 12 even if subscriber unit
base station repeater cell. Additionally, subscriber unit 12
12 is unable to receive rf signals directly from local base
may be located within range of local base station repeater
station repeater cell 10. Thus, two-way communication
cell 10, but may be positioned, for example, in a basement
between local base station repeater cell 10 and subscriber
or other physical location which prevents subscriber unit 12 30 unit 12 is achieved even when subscriber unit 12 is placed
from receiving transmissions from local base station
in an area which is not yet equipped with or is not covered
repeater cell 10 over rf link 14.
by a local base station repeater cell. Additionally, subscriber
unit 12 may be located within range of local base station
With reference next to FIG. 2, a communication system
repeater cell 10, but may be positioned, for example, in a
including a modem 22 for enabling communication between
a local base station repeater cell10 and a subscriber unit 12 35 basement or other physical location which prevents subscriber unit 12 from receiving transmissions from local base
is shown. As shown in FIG. 2, subscriber unit 12 includes
station repeater cell10 over rf link 14. Furthermore, because
switching means such as, for example, an electronic switch
subscriber unit 12 only has to transmit messages to nearby
13 for selecting the path of communication between submodem 22, subscriber unit 12 has a maximum power output
scriber unit 12 and local base station repeater cell 10.
Specifically, in the present embodiment, if subscriber unit 12 40 in the milliwatt range.
is able to detect rf signals from local base station repeater
With reference again to FIG. 2, by including remote
cell10 switching means 13 assumes a default position "Path
receiver 16, the present invention is able to function in a
A". When switching means 13 of subscriber unit 12 selects
standard manner as soon as subscriber unit 12 is able to
Path A, subscriber unit 12 receives rf signals directly from
receive rf signals from local base station repeater cell 10.
local base station repeater cell 10 over rf link 14, and 45 That is, if subscriber unit 12 is moved, for example, from a
transmits data over an rflink 18 to remote receiver 16 which
basement which prevents the subscriber unit from receiving
then transfers the data to local base station repeater cell 10
rf. signals from local base station repeater cell 10 to an area
over hard link 20.
in which subscriber unit 12 can receive rf signals from locai
base station repeater cell 10, conventional two-way comWith reference again to FIG. 2, when subscriber unit 12
is unable to receive rf signals directly from local base station 50 munication is resumed. Thus, subscriber unit 12 would
receive rf signals directly from local base station repeater
repeater cell10, switching means 13 selects "Path B". Thus,
cell 10, switching means 13 of subscriber unit 12 would
if subscriber unit 12 is unable to receive rf signals from local
select Path A, and subscriber unit 12 would respond or
base station repeater cell 10, communication between subtransmit data messages back to local base station repeater
scriber unit 12 and local base station repeater cell10 occurs
along Path B using modem 22. When switching means 13 of 55 cell 10 via remote receiver 16 thereby eliminating the need
for modem 22. Therefore, the present invention is able to
subscriber unit 12 selects Path B, local base station repeater
compliment a standard two-way interactive data broadcast
cell 10 transmits messages to modem 22 via, for example,
network and provide two-way communications even in
telephone line 24 and public switched network 25. Although
conditions which have previously prevented such commua telephone line is used in the present embodiment, the
present invention is also well suited to having local base 60 nications. Additionally, the present invention does not substantially increase the cost of the standard two-way interacstation repeater cell 10 and modem 22 connected by, for
tive data broadcast network, and does not require additional
example cable, or other means. As shown in FIG. 2, modem
local base station repeater cells.
22 communicates with subscriber unit 12 via an rf link 26.
In the present embodiment, rf link 26 is at a frequency of
With reference next to FIG. 3, another embodiment of the
approximately 218-219 MHz. Although a frequency of 65 present invention is shown in which subscriber unit 12
approximately 218-219 MHz is used in the present embodicommunicates directly with a network hub switching center
ment, the present invention is also well suited to the use of
30 via modem 22. As shown in the embodiment of FIG. 3,

5,592,491

6

5
in instances where no local base station repeater cell is
located proximate to subscriber unit 12, two-way interactive
communication is still possible. Because there is no local
base station repeater cell, subscriber unit 12 is unable to
receive rf signals from a local base station repeater cell.
Thus, switching means 13 selects Path B, such that communication to and from subscriber unit 12 occurs through
modem 22.
Referring again to FIG. 3, in the present embodiment,
network hub switching center 30 communicates with
modem 22 over hard wire link 32 and public switched
network 33. Although a telephone line is used in the present
embodiment, the present invention is also well suited to
having local network hub switching center 30 and modem
22 connected by, for example cable, or other means. As
shown in FIG. 3, modem 22 communicates with subscriber
unit 12 via an rf link 26. In the present embodiment, rf link
26 is at a frequency of approximately 218-219 MHz.
Although a frequency of approximately 218-219 MHz is
used in the present embodiment, the present invention is also
well suited to the use of other frequencies such as, for
example, 902 MHz or 45 MHz. Subscriber unit 12 then
responds to messages and transmits data messages to network hub switching center 30 via modem 22. That is,
subscriber unit 12 sends a data message or response over rf
link 26 to modem 22. Modem 22 then relays that message
or response over link 32 back to network hub switching
center 30. Thus, two-way communication between network
hub switching center 30 and subscriber unit 12 is achieved.
With reference still to FIG. 3, in the present embodiment,
modem 22 is connected to network hub switching center 30
through telephone line 32 using, for example, either an 800
or 900 telephone number. The telephone link between subscriber unit 22 and network hub switching center 30 via
modem 22 is broken after approximately 30 seconds allowing for normal use of the telephone line. Use of the link
between subscriber unit 22 and network hub switching
center 30 via modem 22 is protected by a serial number
handshake. Initiation of auto dial-up on a daily schedule by
subscriber unit 12 insures that the data received by subscriber unit 12 remains current.
With reference again to FIG. 3, modem 22 is also adapted
to communicate with a local base station repeater cell when
a local base station repeater cell is located proximate to
subscriber unit 12. That is, modem 22 is also able to transmit
data through line 34 to a local base station repeater cell when
a local base station repeater cell becomes available. Therefore, the present invention is able to compliment a standard
two-way interactive data broadcast network and provide
two-way communications even in conditions which have
previously prevented such communications. Additionally,
the present invention provides two-way communications
even when a local base station repeater cell is not located
proximate to a subscriber unit.
The present invention also provides several substantial
benefits over a standard two-way interactive data broadcast
network. The present invention can be used to provide
wireless facsimile service, or to request pay-per-view services even when the subscriber unit is not able to receive rf
signals from the local base station repeater cell. Likewise,
the present invention also provides for immediate modem
access even when the subscriber unit is located, for example,
at poolside etc. Additionally, a single modem of the present
communication system can be mounted in such a location as
to be able to communicate via an rf link to numerous
subscriber units placed within homes located, for example,
along a single street or within the same neighborhood. In so

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doing, the present communication system is able to collect
data from a number of home appliances, etc.
The foregoing descriptions of specific embodiments of the
present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations
are possible in light of the above teaching. The embodiments
were chosen and described in order to best explain the
principles of the invention and its practical application, to
thereby enable others skilled in the art to best utilize the
invention and various embodiments with various modifications as are suited to the particular us contemplated. It is
intended that the scope of the invention be defined by the
claims appended hereto and their equivalents.
I claim:
1. A two-way communication network comprising:
a network hub switching center;
subscriber units dispersed at various locations within a
predetermined geographic area, said subscriber units
including switching means for selecting a communication path within said network,
local base station repeater cell communicating with identified individual subscriber units within a local base
station geographic area associated with said local base
station repeater cell, said local base station repeater cell
further comprising,
base station data processing and communication unit
for transmitting to a set of said subscriber units
contained within said local base station geographic
area associated with said local base station repeater
cell and receiving from a subset of said set of local
subscriber units multiplexed synchronously related
digital data messages of variable lengths for pointto-point communication between said local base
station repeater cell and said subset of said local
subscriber units,
reception for receiving and processing data messages
from said set of local subscriber units comprising a
local remote receiver disposed within one of a plurality
of cell subdivision sites partitioned from said local base
station geographic area associated with said local base
station repeater cell, said plurality of cell subdivision
sites dispersed over said local base station geographic
area, said local remote receiver being adapted to
receive low power digital messages transmitted from
said local subscriber units within range of said local
remote receiver,
said set of local subscriber units including low power
mobile units located within said local base station
geographic area, each of said local subscriber units
adapted to communicate with said local base station
repeater cell by way of digital data signals of variable
lengths synchronously related to a base station broadcast signal and timed for multiplexed message transmission, and
a modem communicatively coupled to said local subscriber units and said local base station repeater cell for
transferring said multiplexed synchronously related
digital data messages of variable lengths between said
set of local subscriber units and said local base station
repeater cell if said local subscriber units are unable to
directly communicate with said local base station
repeater cell.
2. The base station configuration of claim 1 wherein said
modem and said local subscriber units are communicatively
coupled via an rf link.

5,592,491
7

8

3. The base station configuration of claim 2 wherein said

rf link between said modem and said local subscriber units
is at an rf carrier frequency of approximately 218-219 MHz.
4. The base station configuration of claim 1 wherein said
modem and said local base station repeater cell are communicatively coupled via a telephone line.
5. A method of communicating between subscriber units
and a local base station repeater cell comprising the steps of:
determining whether a subscriber unit located with a base
station geographic area associated with said local base
station repeater cell is receiving a signal from said local
base station repeater cell;
if said subscriber unit is receiving a signal from said local
base station repeater cell, performing the steps of:
transmitting outgoing data from said local base station
repeater cell to said subscriber unit by directly transmitting a first outgoing data signal representative of
said outgoing data from said local base station
repeater cell to said subscriber unit, and
transmitting incoming data from said subscriber unit to
said local base station repeater cell by transmitting a
first incoming data signal representative of said
incoming data from said subscriber unit to a receive
only receiver unit and then transmitting a second
incoming data signal also representative of said
incoming data from said receiver unit to said local
base station; and
if said subscriber unit is not receiving a signal from said
local base station repeater cell, performing the steps of:
transmitting said outgoing data from said local base
station repeater cell to said subscriber unit by transmitting a second outgoing data signal representative
of said outgoing data from said local base station
repeater cell to a modem and then transmitting a
third outgoing data signal also representative of said
outgoing data from said modem to said subscriber
unit, and
transmitting said incoming data from said subscriber
unit to said local base station repeater cell by transmitting a third incoming data signal representative of
said incoming data from said subscriber unit to said
modem and then transmitting a fourth incoming data
signal also representative of said incoming data from
said modem to said local base station.
6. The communication method of claim 5 wherein the step
of transmitting said second outgoing data signal from said
local base station repeater cell to said modem further comprises transmitting said second outgoing data signal from
said local base station repeater cell to said modem via a
telephone line.
7. The communication method of claim 5 wherein the step
of transmitting said third outgoing data signal from said
modem to said subscriber unit further comprises transmitting said third outgoing data signal from said modem to said
subscriber unit via an rf link.
8. The communication method of claim 7 wherein the step
of transmitting said third outgoing data signal from said
modem to said subscriber unit via an rf link further comprises transmitting said third outgoing data signal from said
modem to said subscriber unit at an rf carrier frequency of
approximately 218-219 MHz.
9. The communication method of claim 5 wherein the step
of transmitting said third incoming data signal from said
subscriber unit to said modem further comprises transmitting said third incoming data signal from said subscriber unit
to said modem via an rf link.
10. The communication method of claim 9 wherein the
step of transmitting said third incoming data signal from said

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subscriber unit to said modem via an rf link further comprises transmitting said third incoming data signal from said
subscriber unit to said modem at an rf carrier frequency of
approximately 218-219 MHz.
11. The communication method of claim 5 wherein the
step of transmitting said fourth incoming data signal from
said modem to said local base station repeater cell further
comprises transmitting said fourth incoming data signal
from said modem to said local base station repeater cell via
a telephone line.
12. A digital cellular communication system comprising
in combination:
a cell site divided into a plurality of subdivided zones,
a plurality of subscriber units with identity numbers based
in said cell site,
a cell site communication system including a digital
transmitter for communication with individual identified subscriber units geographically located within said
cell site,
a set of receive only digital receivers positioned in said
subdivided zones, each said digital receiver being
coupled by a transmission link with said cell site
communication system to relay received digital communications,
a set of said subscriber units comprising portable wireless
digital communication units with a limited power digital transmitter having a transmitting power for transmissions within said subdivided zones,
a receiver for reception of digital messages from said cell
site digital transmitter,
a modem communicatively coupled to said local subscriber units and said digital transmitter for transferring
data between said subscriber units and said digital
transmitter if said subscriber units are unable to communicate directly with said digital transmitter.
13. A two-way communication system comprising:
at least one subscriber unit disposed within a predetermined base station geographic area, said at least one
subscriber unit including switching means for selecting
a communication path within said communication system,
a network hub switching center for routing communications from and to said at least one subscriber unit, and
a modem communicatively coupled to said at least one
subscriber unit and said network hub switching center
for transferring multiplexed synchronously related
digital data messages of variable lengths between said
at least one subscriber unit and said network hub
switching center if said at least one subscriber unit is
unable to communicate directly with a local base
station repeater cell, said modem also adapted for
communicating with said local base station repeater
cell if communication therebetween is not otherwise
prevented.
14. The base station configuration of claim 13 wherein
said modem and said at least one subscriber unit are communicatively coupled via an rf link.
15. The base station configuration of claim 14 wherein
said rf link between said modem and said at least one
subscriber unit are at an rf carrier frequency of approximately 218-219 MHz.
16. The base station configuration of claim 13 wherein.
said modem and said network hub switching center are
communicatively coupled via a telephone line.
17. A method of communicating between a subscriber unit
and a network hub switching center in a two-communication
system comprising the steps of:

5,592,491
9
detennining whether a subscriber unit located with a base
station geographic area associated a said local base
station repeater cell is receiving a signal from said local
base station repeater cell;
if said subscriber unit is receiving a signal from said local 5
base station repeater cell, performing the steps of:
transmitting outgoing data from said network hub
switching center to said subscriber unit via said local
base station repeater cell, and
transmitting incoming data from said subscriber unit to 10
said network hub switching center via said local base
station repeater cell; and
if said subscriber unit is not receiving a signal from said
local base station repeater cell, perfonning the steps of:
transmitting said outgoing data from said network hub 15
switching center to said subscriber unit by transmitting a first outgoing data signal representative of said
outgoing data from said network hub switching
center to a modem and transmitting a second outgoing data signal also representative of said outgoing 20
data from said modem to said local base station
repeater cell, and
transmitting incoming data from said subscriber unit to
said network hub switching center by transmitting a
first incoming data signal representative of said 25
incoming data from said subscriber unit to said
modem and transmitting a second incoming data
signal also representative of said incoming data from
said modem to said network hub switching center.
18. The communication method of claim 17 wherein the 30
step of transmitting said first outgoing data signal from said
network hub switching center to said modem further comprises transmitting said first outgoing data signal from said

10
network hub switching center to said modem via a telephone
line.
19. The communication method of claim 17 wherein the
step of transmitting said second outgoing data signal from
said modem to said subscriber unit further comprises transmitting said second outgoing data signal from said modem
to said subscriber unit via an rf link.
20. The communication method of claim 19 wherein the
step of transmitting said second outgoing data signal from
said modem to said subscriber unit via an rf link further
comprises transmitting said data from said modem to said
subscriber unit at an rf carrier frequency of approximately
218-219 MHz.
21. The communication method of claim 17 wherein the
step of transmitting said first incoming data signal from said
subscriber unit to said modem further comprises transmitting said first incoming data signal from said subscriber unit
to said modem via an rf link.
22. The communication method of claim 21 wherein the
step of transmitting said first incoming data signal from said
subscriber unit to said modem via an rf link further comprises transmitting said first incoming data signal from said
subscriber unit to said modem at an rf carrier frequency of
approximately 218-219 MHz.
23. The communication method of claim 17 wherein the
step of transmitting said second incoming data signal from
said modem to said network hub switching center further
comprises transmitting said second incoming data signal
from said modem to said network hub switching center via
a telephone line.

* * * * *

UNITED STATES PATENT AND TRADEMARK OFFICE

CERTIFICATE OF CORRECTION
PATENT NO.
APPLICATION NO.
DATED
INVENTOR(S)

Page 1 of 1

: 5,592,491
:08/348618
: January 7, 1997
:Gilbert M. Dinldns

It is certified that error appears in the above-identified patent and that said Letters Patent is
hereby corrected as shown below:

At column 6, line 65 (in claim 2); column 7, line 1 (in claim 3); and column 7, line 4 (in
claim 4):
The text "base station configuration" should read --two-way communication network-At column 7, line 26 and line 43 (in claim 5):
The text "base station" should read --base station repeater cell-At column 8, line 55 (in claim 14), column 8, line 58 (in claim 15); and column 8, line
62 (in claim 16):
The text "base station configuration" should read --two-way communication system-At column 9, lines 21-22 (in Claim 17):
The text "local base station repeater cell" should read --subscriber unit--

Signed and Sealed this
Seventeenth Day ofNovember, 2009

David J. Kappos
Director of the United States Patent and Trademark Office