U.S. patent application number 10/785660 was filed with the patent office on 2004-08-26 for communications systems for aircraft.
This patent application is currently assigned to Tenzing Communications, Inc.. Invention is credited to Bastian, Fabio, Chan, Philip Seik Poon, Gresham, Simon, Lemme, Peter W..
Application Number | 20040167967 10/785660 |
Document ID | / |
Family ID | 26314343 |
Filed Date | 2004-08-26 |
United States Patent
Application |
20040167967 |
Kind Code |
A1 |
Bastian, Fabio ; et
al. |
August 26, 2004 |
Communications systems for aircraft
Abstract
A system for permitting passengers on board an aircraft to send
and receive electronic data is described. The components of the
system on board the aircraft include a server having a plurality of
nodes to which computer terminals are attached, as desired. The
computer terminals are laptop or palm-top personal computers
belonging to the various passengers on board or fixed terminals
within the aircraft. The server communicates with a wide variety of
different terminals running different operating systems. Each
computer terminal is connected to the server via an aircraft
network. Server has mass storage which contains a database of WWW
pages which can be browsed by passengers using terminals. Server
provides a domain name server (DNS) that masquerades as the
passenger's usual DNS. Server then links the passenger to the
appropriate locally stored WWW page. Server also contains storage
for e-mail messages. Connected to server is one or more radios.
This permits data to be transferred to base station using
communications network. A virtual private network (VPN) connects
station to communications service provider networks, web content
processor, and via links to the Internet, including access to
subscriber ISPs/corporate mail servers and other mail servers.
Points of Presence (POP) provide Internet access and e-mail service
to subscribers of the service while not on the aircraft. POPs can
also be used by communications service provider networks and web
content processors as an alternate means to connect to VPN.
Inventors: |
Bastian, Fabio; (Seattle,
WA) ; Lemme, Peter W.; (Kirkland, WA) ;
Gresham, Simon; (Seattle, WA) ; Chan, Philip Seik
Poon; (Seattle, WA) |
Correspondence
Address: |
DAVIS WRIGHT TREMAINE, LLP
2600 CENTURY SQUARE
1501 FOURTH AVENUE
SEATTLE
WA
98101-1688
US
|
Assignee: |
Tenzing Communications,
Inc.
Seattle
WA
|
Family ID: |
26314343 |
Appl. No.: |
10/785660 |
Filed: |
February 24, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10785660 |
Feb 24, 2004 |
|
|
|
09487752 |
Jan 19, 2000 |
|
|
|
6757712 |
|
|
|
|
Current U.S.
Class: |
709/206 |
Current CPC
Class: |
H04L 61/1511 20130101;
H04L 29/12066 20130101; H04W 84/06 20130101; B64D 11/0015 20130101;
H04L 12/2856 20130101; H04L 51/38 20130101; H04L 69/329 20130101;
B64D 11/00155 20141201; H04L 2012/4028 20130101; H04L 67/2842
20130101; H04L 67/289 20130101; H04L 67/02 20130101; H04L 67/2852
20130101; H04L 67/12 20130101; H04L 67/2814 20130101; H04B 7/18506
20130101 |
Class at
Publication: |
709/206 |
International
Class: |
G06F 015/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 1999 |
WO |
PCT/AU99/00737 |
Apr 28, 1999 |
GB |
9909825.3 |
Sep 8, 1998 |
GB |
9819587.8 |
Claims
1. A system for transmitting electronic data between a computer
terminal on an aircraft and a terrestrial base station, the system
comprising: a telephone network at least partially secured to the
aircraft for providing telephone service to aircraft passengers; a
server mounted upon or within the aircraft and coupled to the
telephone network for communicating with the computer terminal over
the telephone network, wherein the terminal is disposed remotely
from the server and is coupled to the telephone network; and a
terrestrial base station for selectively communicating with the
server to allow the data to be passed between the base station and
the terminal over the telephone network.
2. The system of claim 1 wherein the base station communicates with
the server via one or more wireless links, each of the wireless
links being a satellite link, a cellular telephone link, a
microwave link or a NATS compatible link.
3. The system of claim 1 wherein the base station or server
determine which of a plurality of wireless links to employ based
upon the availability of each of the plurality of links, a relative
cost of each of the plurality of links, or a relative speed of each
of the plurality of links.
4. The system of claim 1 wherein the base station is configured to
provide a first signal indicative of whether the data is text, a
selected file type, an attachment, or a graphic image, and wherein
the terminal is configured to generate a second signal in response
to the first signal confirming that the data is to be transmitted
from the base station to the terminal.
5. The system of claim 1 wherein the base station stores electronic
data to be transmitted from the base station to the server, and the
server stores electronic data to be transmitted from the server to
the base station, wherein the server and base station communicate
with each other intermittently, and wherein the server determines
when to transmit the stored data on the basis of the amount of time
the aircraft has been in flight or on the basis of an amount of
data stored.
6. The system of claim 1 wherein the base station is configured to
generate a trigger signal between the base station and the server
when a predetermined amount of data has been stored by the base
station, to initiate transmitting of the stored data to the
server.
7. The system of claim 1 wherein the server notifies the base
station of pending e-mail messages not received by a computer
terminal aboard the aircraft, wherein the computer terminal has an
e-mail address, and wherein the base station is configured to store
and resend, to the e-mail address, the pending e-mail messages
after the aircraft arrives at a destination.
8. The system of claim 1 wherein the server notifies the base
station of e-mail messages, from a mail server, that have been
received by the computer terminal aboard the aircraft, wherein the
computer terminal has an e-mail address, and wherein the base
station is configured to contact the mail server for deletion of
the e-mail messages that have been received by the computer
terminal.
9. The system of claim 1, further comprising a CEPT interface
coupled to the telephone network and to the server.
10. The system of claim 1 wherein the server includes a database of
information, the database being updated periodically by
transmission of electronic data from the base station to the
server, and wherein the server allows the terminals to access the
database with a web browser.
11. A system for transmitting electronic data between a terrestrial
base station and a plurality of passenger computer terminals
coupled to a network on an aircraft, the system comprising: a
database for storing e-mail messages for the plurality of passenger
computer terminals; and a server secured to the aircraft and
coupled to the database and to the plurality of passenger computer
terminals via the network, wherein the server and database are
configured to collect and store a plurality of e-mail messages from
the plurality of passenger computer terminals before establishing
an intermittent wireless link with the base station, and configured
to transmit the plurality of e-mail messages as a group over the
link to the base station when the aircraft is in flight and when
the server determines to initiate the transmission.
12. The system of claim 11 wherein the server and database store
e-mail messages transmitted to the aircraft over the wireless link
for at least one of the plurality of passengers, despite the one
passenger's computer terminal not being logged into the server over
the network.
13. The system of claim 11 wherein the server provides installer
software for selective loading to the plurality of passenger
computer terminals, wherein the installer software automatically
changes access settings of at least some of the plurality of
passenger computer terminals for accessing and exchanging e-mail
with the server over the network, and automatically returns the
access settings to a prior condition afterwards.
14. The system of claim 11 wherein the server is configured to
employ Intelligent Mail Management (IMM) and to communicate with
the plurality of passenger computer terminals under a
Point-To-Point (PPP) protocol.
15. The system of claim 11 wherein the server is configured to
compress the plurality of e-mail messages before transmission over
the wireless link.
16. The system of claim 11 wherein the terminal receives from the
base station a first signal indicative of a type of attachment
associated with an e-mail message, and wherein the terminal is
configured to transmit to the base station a second signal in
response to the first signal requesting that the attachment be
transmitted from the base station to the server over the wireless
link.
17. The system of claim 11 wherein the server determines when to
transmit the plurality of e-mail messages based on the amount of
time the aircraft has been in flight or an amount of data
stored.
18. The system of claim 11 wherein the server is configured to
receive from the base station a trigger signal when a predetermined
amount of data has been stored by the base station, and in response
thereto, to initiate receiving the stored data from the base
station.
19. The system of claim 11 wherein the server is configured to
monitor system parameters of the aircraft including passenger doors
open/closed status and aircraft airborne/landed status, and to
communicate with the base station for e-mail message transfer based
on the system parameters of the aircraft.
20. The system of claim 11 wherein the server is configured to
monitor a status of a scheduled flight of the aircraft including a
beginning and end of the flight, if the flight is cancelled, or if
the flight is held away from a gate for an extended period of time,
and wherein the server is configured to communicate with the base
station for e-mail message transfer based on the flight status of
the aircraft.
21. The system of claim 11 wherein the server provides a domain
name server and automatically receives, and transmits to the base
station, mail server addresses, user id's and passwords, including
applicable firewall access information, from the plurality of
passenger computer terminals when each passenger attempts to
retrieve e-mail.
22. The system of claim 11 wherein the server database includes a
plurality of web pages, and wherein the provides a domain name
server and automatically redirects passenger DNS requests to
appropriate web pages.
23. The system of claim 11 wherein the database includes a
plurality of web pages, and wherein the server provides a domain
name server that records passenger requested URLs and provides
requested URLs to the base station for updating the plurality of
web pages in the database.
24. The system of claim 11 wherein the server receives from the
base station a summary of an attachment associated with an e-mail
message and provides a hypertext link for accessing the attachment
by a passenger, and wherein the server is configured to receive the
attachment over the wireless link if the passenger provides a
payment signal.
25. The system of claim 11 wherein the server receives from the
base station a summary of an attachment and a hypertext link for
sending the attachment by a passenger, and wherein the server is
configured to send the attachment over the wireless link to the
base station if the passenger provides an authorization signal.
26. The system of claim 11 wherein the server is configured to
permit communications between the plurality of passenger computer
terminals aboard the aircraft via the network.
27. The system of claim 11, further comprising a plurality of
passenger computer terminals secured to the aircraft and coupled to
the network.
28. The system of claim 11 wherein the database includes a
plurality of video games, compressed format movies or audio files,
and wherein the server and database provide the video games, movies
or audio files to a plurality of passengers aboard the aircraft via
the network.
29. The system of claim 11 wherein the database includes a
plurality of web pages, wherein the plurality of web pages lack
links to other web pages not stored in the database, and wherein
the server and database provide search engine functions to permit
the plurality of passenger computer terminals to search and access
desired web pages in the plurality of web pages.
30. The system of claim 11 wherein the database includes a
plurality of web pages, and wherein the server and database load
and update the plurality of web pages under differential management
proxy cache operations to load a predetermined number of levels
from selected web sites, and to update changes in web page code
without reloading each web page.
31. The system of claim 11 wherein the database includes a
plurality of web pages, and wherein the server and database update
predetermined data in the plurality of web pages via the wireless
link, wherein the predetermined data includes share prices, weather
updates or news flashes.
32. The system of claim 11 wherein the database includes a
plurality of web pages, and wherein web pages in the database are
updated by connection with a data loader at the base station, by
physical replacement of a mass storage device containing the
database, remotely by a wired link, or remotely by the wireless
link.
33. An aircraft computer communication system for use on an
aircraft, wherein the aircraft carries a plurality of passengers
having computer terminals, the system comprising: a database for
storing e-mail messages for the plurality of passenger computer
terminals; a network hub located on the aircraft for allowing the
transfer of the e-mail messages to the passenger computer
terminals; and a first port and a second port located on the
aircraft for coupling the database with passenger computer
terminals and for allowing the establishment of a first network
node and a second network node respectively, and wherein the
network hub routes selected e-mail messages between the database
and the terminals.
34. The system of claim 33 wherein the first and second ports form
ports of a passenger telephone system.
35. The system of claim 33 wherein the first node is coupled to a
telephone system on the aircraft with a CEPT-E1 connection.
36. The system of claim 33, further comprising a server coupled to
the database.
37. A method for transmitting electronic data between a plurality
of passenger computer terminals on an aircraft and a terrestrial
base station, the method comprising: collecting and storing a
plurality of e-mail messages for the plurality of passenger
computer terminals at the base station; establishing an
intermittent wireless link with the base station; and transmitting
the plurality of e-mail messages as a group over the link between
an airborne database and the base station.
38. A method according to claim 37 wherein the establishing
includes establishing one or more wireless links, the wireless
links being a satellite link, a cellular telephone link, a
microwave link, or a NATS compatible link.
39. A method according to claim 37 wherein establishing includes
identifying a desired link from a plurality of links based on the
availability of each link, the relative cost of each link, or the
relative speed of each link.
40. A method according to claim 37 wherein transmitting includes
transmitting data using SMTP, HTTP, POP3 or IMAP protocol.
41. A method according to claim 37 wherein establishing includes
identifying a desired base station from a plurality of base
stations based on a available remaining capacity of the base
stations or a least expensive communication route available by the
base stations.
42. A method according to claim 37, further comprising receiving a
trigger signal indicating e-mail messages stored at the base
station await retrieval.
43. The method of claim 37 wherein storing includes storing store
e-mail messages transmitted to the aircraft over the wireless link
for at least one of the plurality of passengers, despite the one
passenger's computer terminal not being logged on.
44. The method of claim 37, further comprises automatically
changing access settings of at least some of the plurality of
passenger computer terminals for accessing and exchanging e-mail,
and automatically returning the access settings to a prior
condition afterwards.
45. The method of claim 37, further comprises dynamically assigning
IP addresses to at least some of the plurality of passenger
computer terminals for accessing and exchanging e-mail over an
Ethernet network, wherein the at least some passenger computer
terminals have static IP addresses and wherein Ethernet network
properties of the at least some passenger computer terminals remain
unchanged.
46. The method of claim 37, further comprising monitoring system
parameters of the aircraft including passenger doors open/closed
status, aircraft airborne/landed status, flight cancellation, or
extended aircraft waiting while away from a gate, and communicating
with the base station for e-mail message transfer based on the
system parameters of the aircraft.
47. The method of claim 37, further comprising automatically
collecting from each passenger and transmitting to the base
station, mail server addresses, user id's and passwords and
firewall access information from the plurality of passenger
computer terminals when each passenger attempts to retrieve
e-mail.
48. The method of claim 37, further comprising automatically
collecting from each passenger e-mail from a mail server logically
positioned behind a firewall security measure, without the need for
the passenger computer terminal being available.
49. The method of claim 37, further comprising providing a summary
of an attachment associated with an e-mail message and a hypertext
link for accessing the attachment, and receiving the attachment
over the wireless link if a passenger provides a payment
signal.
50. The method of claim 37, further comprising storing a
predetermined number of levels for a plurality of web pages, and
updating changes in web page code for the plurality of web pages
without reloading each web page.
51. A system for transmitting electronic data between a computer
terminal on an aircraft and a terrestrial base station, the system
including: a server mounted upon or within the aircraft for
communicating with the computer terminal wherein the terminal is
disposed remotely from the server; and a terrestrial base station
for selectively communicating with the server to allow the data to
be passed between the base station and the terminal.
52. The system of claim 51 wherein the base station communicates
with the server via a link selected from one or a combination of:
one or more wireless links; and one or more wire links.
53. The system of claim 51 wherein the server communicates with a
plurality of remotely disposed computer terminals located on the
aircraft for allowing communication of the electronic data between
the base station and the respective terminals.
54. The system of claim 51 wherein the terrestrial base station
selectively communicates with an Internet service provider (ISP) or
corporate private network to collect the electronic data and
provide it to the terminal via the server.
55. A method for transmitting electronic data between a plurality
of passenger computer terminals on an aircraft and a terrestrial
base station, the method comprising: collecting and storing a
plurality of e-mail messages from the plurality of passenger
computer terminals at an airborne data base; establishing an
intermittent wireless link with the base station; and transmitting
the plurality of e-mail messages as a group over the link from the
airborne database to a base station.
56. The method of claim 55 wherein the base station transmits at
least one of the plurality of e-mail messages to a destination mail
server for at least one of the plurality of passengers, despite the
one passenger's computer terminal not being logged on.
57. The method of claim 55, further comprises dynamically assigning
IP addresses to at least some of the plurality of passenger
computer terminals for accessing and exchanging e-mail over an
Ethernet network.
58. The method of claim 55, further comprising automatically
collecting from each passenger e-mail from a mail server logically
positioned behind a firewall security measure.
Description
TECHNICAL FIELD
[0001] The present invention relates to a communication system for
aircraft and in particular to a system for transmitting electronic
data between an aircraft and a terrestrial base station.
[0002] The invention has been developed primarily for use with
passenger aircraft and will be described hereinafter with reference
to that application. However, it will be appreciated that the
invention is not limited to that particular field of use.
BACKGROUND OF THE INVENTION
[0003] In recent times, portable computers such as "laptop" PCs and
devices such as the Apple.RTM. Newton or other palm-held devices
(PDAs) running Microsoft.RTM. Windows CE, for example, have become
available. There have been commensurate improvements in mobile or
cellular telephone technology and in protocols for transmitting
computer-generated data across cellular networks. By employing a
PCMCIA modem, for example, which allows data to be transferred
between the laptop or PDA and mobile telephone, these twin
developments have allowed e-mail messages and other electronic data
to be sent and received by an individual at one of many locations,
without the need to connect via a fixed land telephone line.
[0004] Several communications networks for providing
telecommunications to airborne users are also known. For example,
the North American Telephone System (NATS), including providers
such as AT&T and Airfone, have installed terminals in many
commercial aircraft to allow passengers to connect a laptop or PDA
and transfer data from the passenger's seat.
[0005] In addition to terrestrial based aeronautical
communications, satellite service providers such as Inmarsat
provide airborne passengers communications from virtually any
global location. Similar services are also offered by Iridium, who
has launched another network of satellites. Furthermore, other
satellite providers have or are launching constellations of
satellites with the intention of providing airborne passenger
communications.
[0006] One serious drawback of existing aeronautical passenger
communications is the expense. In most cases, the passenger
connects the laptop or PDA to a seat mounted handset using an
integrated RJ11 jack. The passenger must make a modem connection to
their ground based access server, provide authentication
information, and then retrieve or send data. This process is
generally technically challenging and unreliable. Even for the
transfer of small amounts of data, one or more calls of one or more
minutes is necessary. Furthermore, the existing speed of
transmission, defined as bits per second (bps), is relatively
slow--for example, the INMARSAT satellite services currently limit
the data rate for passenger modem communications to 2400 bps. Thus,
the time taken to transfer large amounts of electronic data, and
the consequent expense, can become prohibitive.
[0007] In addition, the reliability of connection when employing a
wireless link has been perceived as a major drawback during
transmission of data in this way.
[0008] Thus, until now, the use of portable computers on aircraft,
for sending and receiving electronic mail and browsing World Wide
Web (WWW) sites has not been deemed feasible.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to overcome or
substantially ameliorate one or more of the disadvantages of the
prior art, or at least to provide a useful alternative.
[0010] According to a first aspect of the invention there is
provided a system for transmitting electronic data between a
computer terminal on an aircraft and a terrestrial base station,
the system including:
[0011] a server mounted upon or within the aircraft for
communicating with the computer terminal wherein the terminal is
disposed remotely from the server; and
[0012] a terrestrial base station for selectively communicating
with the server to allow the data to be passed between the base
station and the terminal.
[0013] Preferably, the base station communicates with the server
via a link selected from one or a combination of: one or more
wireless links; and one or more wire links. More preferably, the
base station communicates with the server via one or more wireless
links, each of those wireless links being selected from the group
comprising: a satellite link; a cellular telephone link; a
microwave link; a NATS compatible link; and another communication
system. Even more preferably, the selection of the or each link is
dependent upon one or more of: the availability of each link; the
relative cost of each link; and the relative speed of each
link.
[0014] Preferably also, the system includes a plurality of spaced
apart terrestrial base stations and the server communicates
selectively with one or more of the stations. More preferably, the
base station with which the server selectively communicates is
dependent upon the position of the aircraft with respect to the
stations.
[0015] In a preferred form, the server communicates with a
plurality of remotely disposed computer terminals located on the
aircraft for allowing communication of the electronic data between
the base station and the respective terminals.
[0016] Preferably, the terrestrial base station selectively
communicates with an Internet service provider (ISP) or corporate
mail server to collect the electronic data and provide it to the
terminal via the server.
[0017] More preferably, the data is communicated between the server
and the terminal using one or more of: SMTP; HTTP; POP3; or IMAP.
More preferably, the data is collected from the ISP or corporate
mail server and delivered to the base station using POP3 or
IMAP.
[0018] More preferably, the base station is able to communicate
with a corporate mail server that is behind a firewall. The
corporate subscriber can provide firewall static user id and
password once when signing up for service, arrange for VPN 150 to
have secure access behind the corporate firewall; or the corporate
subscriber can provide dynamic user id and password information the
first time requesting e-mail retrieval.
[0019] In a preferred form, the base station includes means for
providing a first signal indicative of the structure of the data
and the terminal includes means for generating a second signal in
response to the first signal confirming that the data is to be
transmitted to the terminal. More preferably the first signal is
indicative of one or more of the following: text; file type;
attachments; graphics; backgrounds; and the like. Even more
preferably, the second signal confirms to the base station which
portions of the data are to be transmitted.
[0020] Preferably, the base station stores electronic data to be
transmitted from the base station to the server, and the server
stores electronic data to be transmitted from the server to the
base station, the server and base station communicating with each
other intermittently.
[0021] In a preferred form, the server includes a database of
information, the database being updated periodically by
transmission of electronic data from the base station to the
server. More preferably, the server allows the terminals to access
the database. Even more preferably, the terminals access the
database with a web browser.
[0022] Preferably also, the server communicates with that base
station which is nearest to the aircraft. More preferably, the
server determines which of the base stations is nearest by
determining the current location of the aircraft. More preferably,
the server communicates with one only of the base stations.
Alternatively, the server communicates with selectively with more
than one of the base stations, the selection being made on the
basis of the available remaining capacity of the respective base
stations.
[0023] Preferably, the server communicates selectively with one of
the base stations, the selection being made on the basis of the
least expensive communication route that is made available by the
respective base stations.
[0024] In a preferred form the computer terminal is suitable for
either browsing the Internet or sending and retrieving e-mail. More
preferably, the terminal is a portable personal computer. However,
it is also preferred that the terminal is a PDA, or a fixed
terminal installed as a part of the aircraft, for example as a part
of the in-flight entertainment system.
[0025] According to a second aspect of the invention there is
provided a method for transmitting electronic data between a
computer terminal on an aircraft and a terrestrial base station,
the method including the steps of:
[0026] providing a server mounted upon or within the aircraft for
communicating with the computer terminal wherein the terminal is
disposed remotely from the server; and
[0027] selectively communicating between a terrestrial base station
and the server to allow the data to be passed between the base
station and the terminal.
[0028] According to a third aspect of the invention there is
provided an aircraft computer communication system including:
[0029] a first port and a second port located on the aircraft for
allowing the establishment of a first network node and a second
network node respectively; and
[0030] a network located on the aircraft for linking the first node
and the second node and allowing communication between the first
node and the second node.
[0031] Preferably, the network includes a telephone system and the
second node is connected to the telephone system. More preferably,
the second node is connected to the telephone system with a modem
connection. Even more preferably, the first node is connected to
the telephone system with a CEPT-E1 connection. In a further
preferred form the CEPT-E1 connection complies with an ARINC 746,
attachment 11 radio bearer system interface.
[0032] Preferably also, the first and the second network nodes are
a server and a computer terminal respectively.
[0033] According to a fourth aspect of the invention there is
provided an aircraft computer network including:
[0034] a network hub located on an aircraft for allowing the
transfer of first electronic data from the network to a base
station;
[0035] a first port and a second port located on the aircraft for
allowing the establishment of a first network node and a second
network node respectively, wherein the nodes transfer respective
second and third electronic data to the network via the hub such
that the first data includes selected portions of the second
data.
[0036] Preferably, the second data includes selected portions of
the third data.
[0037] According to an fifth aspect of the invention there is
provided a method of communicating between a first node and a
second node of an aircraft computer network, the method including
the steps of:
[0038] locating a network hub on an aircraft for allowing the
transfer of first electronic data from the network to a base
station;
[0039] locating a first port and a second port on the aircraft for
allowing the establishment of the first network node and the second
network node respectively, wherein the nodes transfer respective
second and third electronic data to the network via the hub such
that the first data includes selected portions of the second
data.
[0040] Preferably, the second data includes selected portions of
the third data.
[0041] According to another aspect of the invention there is
provided a method of communicating between a first node and a
second node of an aircraft computer network, the method including
the steps of:
[0042] locating a network hub on an aircraft for allowing the
transfer of first electronic data from a base station to the
network;
[0043] locating a first port and a second port on the aircraft for
allowing the establishment of a first network node and a second
network node respectively, wherein the network transfer respective
second and third electronic data to the nodes via the hub such that
the second data includes selected portions of the first data.
[0044] Preferably, the third data includes selected portions of the
second data.
[0045] In the preferred embodiment each base station is capable to
connecting to the Internet, and able to communicate with various
Internet service providers and computing resources throughout the
world. Thus, rather than each passenger on the aircraft connecting
individually via a satellite link, for example, to an Internet
service provider, the passengers all connect to a central server on
board the aircraft. This airborne server then establishes a
connection a base station as necessary. Thus, the efficiency of
data transmission between a passenger and their normal ISP may be
improved, and the overall cost of transmission to and from the
aircraft may be significantly reduced. Further efficiency is gained
by using compression software to reduce the quantity of data (bits)
that needs to be sent between the airborne server and a base
station. A Radius client interface is provided by the server/base
station to interact with Radius servers for end user authentication
and network access requests.
[0046] In one configuration, the server and the base station can
store and forward requests; for example by a passenger to retrieve
e-mail from their ISP/corporate mail server. This may require the
passenger's laptop to be connected for the duration of the data
exchange between the airborne server and a base station, which can
be restricted to 2400 bps or less. Furthermore, there may be no
means to restrict or control the flow, for example, of very large
attachments.
[0047] In another configuration, the server and base station can
provide a proxy service, whereby, for example, the base station can
retrieve e-mail on behalf of the passenger, including behind a
corporate firewall, and transmit this information to the airborne
server, and the airborne server can transmit passenger provided
e-mail to the base station, in both cases, without the passenger's
laptop being connected to the aircraft network. The airborne server
collects the e-mail and provides it to the passenger on demand. The
aircraft network data rate is not necessarily restricted by the
data rate of communications between the airborne server and a base
station.
[0048] The aircraft network may be comprised of a dedicated cables
and circuitry between the server and dedicated ports in the seat.
Alternatively, the aircraft network may be wholly comprised within
an existing aircraft system, such as the airborne telephone
system.
[0049] The system of the preferred embodiment thus provides for
e-mail transmission and reception, for example, for a larger number
of users, each having different Internet Service Providers or
corporate e-mail accounts, which may in turn be in different
countries.
[0050] The protocol used for sending data from the or each remote
computer terminal to the server, and from the server to the or each
remote computer terminal, is preferably TCP/UDP. Protocols
supported by this connection include FTP, SMTP, HyperText Transfer
Protocol (HTTP), POP3, IMAP and DNS.
[0051] Preferably also, any data to be sent from the base station
to the server is first analyzed to determine its structure (unlike
store and forward principals). Most preferably, the base station
sends to the server structure data indicative of the structure, the
structure data being then communicated to a predetermined one of
the remote computer terminals. This technique prevents large
attachments, for example, to e-mail messages from being sent across
the relatively low bandwidth link between the base station and the
server, other than where the relevant passenger agrees to pay a
nominated fee. That is, upon being informed of the data structure,
the user of the remote terminal within the aircraft is provided
with the choice as to whether the attachment need be obtained. The
passenger can interact with the server through the use of server
generated web pages.
[0052] Preferably, the base station is arranged to store electronic
data to be transmitted from the base station to the server, and the
server is arranged to store electronic data to be transmitted from
the server to the base station, the server and base station
communicating with each other intermittently.
[0053] To minimize cost and improve efficiency, the server and base
station preferably each store electronic data as they receive it
from the individual users on the plane and their Internet service
providers/corporate accounts respectively. In one embodiment, a
connection is then made intermittently. During each connection,
data is exchanged between the server and base station, and after
exchange has been completed, the connection is terminated. For
example, in one embodiment the server and base station exchange
data for one minute or so, every fifteen minutes. Compression
software is used to minimize data transfer.
[0054] In one preferred form the system includes a plurality of
base stations. For example, each Continent may have a separate base
station. The server preferably connects with that base station
which it is nearest to at a given time. In other embodiments,
however, a single base station is utilized.
[0055] The server also preferably acts as a virtual WWW. For
example, in one embodiment the server stores a plurality of pages
of information from a number of web sites. Because this information
is stored on board the aircraft, it may be accessed very rapidly
and without significant communications expense. The server
redirects the passenger browser to appropriate web pages available
locally.
[0056] The external link, however, allows updating of the stored
pages from time to time. Most preferably, the web pages are stored
in a cache which is updateable differentially. That is, as changes
to a particular web page are effected, only the new or amended
parts of each page need be sent via the wireless link, rather than
the full page.
[0057] Preferably, the server includes a mass storage device which
is updated to the latest available content prior to departure of
the aircraft from a port of call.
[0058] Preferably also, the passenger establishes a PPP connection
between the remote computer terminal and the server, normally using
a specially provided dialer application. In other embodiments,
however, the dialer application is manually configured. Even more
preferably, the server captures the passenger user identification
and password to be used by a Radius client for user authentication
against a Radius server and if applicable a corporate firewall.
[0059] The base station preferably receives authentication from a
Radius server, delivering e-mail from the passenger and retrieving
the passengers e-mail from the passengers Mail server. More
preferably, the base station provides the passenger e-mail to the
server, with indications of any additional attachments and the base
station provides any passenger instant messaging, which will be
delivered to the passenger's terminal and displayed using a
resident application, such as the dialer. Even more preferably, the
server provides the e-mail to the passenger e-mail client with the
passenger subsequently retrieves e-mail. Further preferments
include interacting the passenger and the server to determine if
any additional attachments should be retrieved and, if so,
retrieving the attachments from the base station.
[0060] Preferably, the passenger browses the world wide web content
provided by the server.
[0061] In a preferred form, the server/base station use Simple
Network Management Protocol (SNMP) for network monitoring.
[0062] Preferably also, the server and base station maintain
accounting of all transactions for billing purposes. Preferably
also, the server and base station monitor passenger activities and
recording these activities for other uses. More preferably the
server and base station determine when to cease retrieving e-mail
on behalf of the passenger and when to delete e-mail messages that
have been delivered to the passenger computer terminal within the
passenger e-mail mail server if required.
[0063] It will be understood that preferred features of this method
may correspond to the preferred features of the system of the
present invention.
[0064] Unless the context clearly requires otherwise, throughout
the description and the claims, the words `comprise`, `comprising`,
and the like are to be construed in an inclusive sense as opposed
to an exclusive or exhaustive sense; that is to say, in the sense
of "including, but not limited to."
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] Preferred embodiments of the invention will now be
described, by way of example only, with reference to the
accompanying drawings.
[0066] FIG. 1 is a schematic overview of a system according to the
present invention.
[0067] FIG. 2 is a schematic sectional view of a part of an
aircraft.
[0068] FIG. 3 is a flow diagram illustrating the protocols for
transferring e-mail or other data from the aircraft.
[0069] FIG. 4 is a flow diagram illustrating the protocols for
transferring e-mail or other data to the aircraft.
[0070] FIG. 5 is a schematic view of an alternative system
according to the invention.
[0071] FIG. 6 is a schematic representation of the interaction of
an aircraft and the terrestrial part of the system of FIG. 5 as it
travels from a point of departure to a destination.
[0072] FIG. 7 is a block diagram of an aircraft network according
to another aspect of the invention.
[0073] FIG. 8 is a block diagram of an alternative aircraft network
according to the invention.
[0074] FIG. 9 is a block diagram of a further alternative aircraft
network according to the invention.
DETAILED DESCRIPTION
[0075] Referring to FIG. 1, a system for permitting passengers on
board an aircraft to send and receive electronic data is shown.
Those parts of the system located on board the aircraft are shown
within the region bounded by broken lines and labelled 10 in FIG.
1. The components of the system on board the aircraft include a
server 20 having a plurality of nodes 30 to which computer
terminals 40a, 40b and 40c are attached, as desired. The computer
terminals in the embodiment shown are laptop or palm-top personal
computers belonging to the various passengers on board. As will be
explained below, the server communicates with a wide variety of
different terminals running different operating systems. Each
computer terminal is connected to the server 20 via an aircraft
network 50.
[0076] The server 20 has mass storage which contains a database of
WWW pages which can be browsed by passengers using their computer
terminals 40a, 40b and 40c. Server 20 provides a domain name server
(DNS) that masquerades as the passenger's usual DNS. Server 20 then
links the passenger to the appropriate locally stored WWW page.
[0077] The server 20 also contains storage for e-mail messages.
[0078] Connected to the server 20 is one or more radios 60. This
permits data to be transferred to base station 90, using
communications networks 80.
[0079] A virtual private network (VPN) 150 connects base station 90
to communications service provider networks 80, web content
processor 190, and via links 180 to the Internet 160. Points of
Presence (POP) 170 provide Internet access and e-mail service to
subscribers of the service while not on the aircraft. POPs 170 can
also be used by communications service provider networks and web
content processors as an alternate means to connect to VPN 150.
[0080] Base station 90 connects to Internet service provider (ISP)
or corporate mail servers 110a, 110b and 110c, which host the mail
servers of the respective passengers on board the aircraft who are
connected to server 20.
[0081] Thus electronic mail sent from terminal 40a on board the
aircraft is first forwarded to server 20 where it is stored. The
server determines the appropriate time to initiate a data exchange
with station 90. This can be when sufficient data is awaiting
transmission from server 20, or when the time since the last
exchange exceeds a time limit (15 minutes), or when station 90
signals to server 20 via communications service provider network 80
and radio 60. Any e-mail messages stored on server 20 since the
previous connection was made are then transmitted to station 90.
Station 90 forwards the or each e-mail message on to their eventual
destinations Mail servers 195.
[0082] In one embodiment, station 90 signals server 20 with a
trigger signal which indicates that data in the form of e-mail
messages is stored by the station and awaits retrieval. The server
then signals the base station to retrieve this data, which is then
transmitted to the server.
[0083] In a further embodiment, data is transmitted from server 20
to base station 90 at intervals based on predetermined periods of
time that the aircraft has been in flight.
[0084] Similarly, any messages generated by the user of terminal
40b are also sent to server 20 for storage, and forwarded to
station 90 along with the stored messages from the other
passengers. The station 90 then forwards messages from the computer
terminal 40b on to their eventual destinations as well.
[0085] The general procedure for obtaining e-mail messages from the
Internet service providers or corporate accounts of the various
passengers is similar to the procedure for sending e-mail messages
from the various terminals 40a, 40b, 40c on the aircraft. Once a
passenger connects a PC to aircraft network 50 and then connects to
server 20, the passenger initiates e-mail retrieval. Server 20
accepts the request for e-mail and collects the passenger Mail
server address, user id and password. If necessary, a corporate
subscriber can activate previously setup firewall services, and
provide additional username and password information. This
information is passed to base station 90 via radio 60 and
communications service provider networks 80. Base station 90
contacts ISPs/corporate servers 110a,b,c and collects any e-mail
for the passengers using their user IDs and passwords. Base station
90 continues to collect e-mail from ISPs/corporate servers 110a,b,c
for the duration of the flight that the passengers are on. When a
connection is established between server 20 on board the aircraft
and station 90, that stored e-mail message or messages are
transmitted from station 90 to server 20. This procedure is usually
simultaneous with the transmission of e-mail messages in the other
direction from server 20 to station 90.
[0086] Once e-mail messages have been received at server 20, they
are retrieved by the respective passenger's computer terminals, 40a
and 40b via the aircraft network 50 when the passenger subsequently
connects to server 20 and retrieves mail.
[0087] The system includes a single base station. However, in other
embodiments, such as that illustrated in FIG. 5, the system
includes a number of base stations located at spaced apart
locations on the surface of the planet.
[0088] Returning to the system of FIG. 1, as the aircraft flies
from its departure airport towards the destination airport,
aircraft system 130 indicates to server 20 the location of the
aircraft at regular intervals.
[0089] Having provided a brief overview of the system, a detailed
description of the software and hardware of the system will now be
provided with reference to the FIGS. 2, 3 and 4.
[0090] Referring to FIG. 2, a section through an aircraft fuselage
is shown schematically at 200. Features common to FIGS. 1 and 2 are
labelled with like reference numerals.
[0091] The part of the system on board the aircraft comprises
server 20, mounted within a hold 210 of the aircraft. In other
embodiments server 20 is mounted elsewhere within the aircraft. In
the specific embodiment described, however, this server is
configured to provide proxy Internet services. Such a server is
capable of acting both as a server and as an Internet gateway. As
described in connection with FIG. 1, the server is connected to the
aircraft network 50, to the aircraft systems 130, and is connected
to radios 60.
[0092] A PPP connection is made between each passenger's portable
computer (such as 40b) and server 20. When a passenger wishes to
connect to server 20 from his or her portable computer 40b, a cable
290 is used. In one embodiment, one end of cable 290 is inserted
into the serial RS-232 port of the portable computer, and the other
end thereof is plugged into the socket in the armrest 230. In other
embodiments other cabling and connector combinations are utilized,
such as connections to the Universal Serial Bus, or the PC modem.
In any event, at this point, a hardware connection has been made
between the individual portable computer 40b and aircraft network
50.
[0093] Preferably, the connection from aircraft network 50 includes
the provision of power to the portable computers or other devices
so that they need not run on battery power alone. In some
embodiments, however, a power supply socket is provided in armrest
230 as well.
[0094] The software requirements for connecting to server 20 will
now be described. It will be understood that the system is designed
to permit access by many different types of portable computer, such
as a "laptop" personal computer, a palm-top computer (PDA) running
the Microsoft.RTM. Windows CE operating system, the Apple.RTM.
Newton notebook or any other portable device, and the term "remote
computer terminal" is to be construed accordingly. It will also be
appreciated that this term is also intended to encompass any
electronic device which is capable of PPP communication, which may
include fixed terminal on the aircraft, for example a part of the
in-flight entertainment equipment. The desirability of allowing
different platforms to connect to the server is why a PPP
connection between the computer and the server is preferred. PPP
connections allow Point-to-Point Protocol (PPP) transmissions
between the computer and server, PPP not being limited to carrying
TCP/IP traffic and being capable of piggy-backing other network
protocols such as IPX, SPX and AppleTalk.
[0095] Preferably installer software is provided to each user of
the system. More preferably the installer software is obtainable
from one or more of the following sources: pre-flight access to an
Internet site; pre-flight e-mail; floppy disk; or any other
suitable means. Typically different installer software will be
required for use with different operating systems. In use, the
installer software is executed by the passenger either during or
prior to the flight. The software adds a new PPP service. The
details of how such a PPP service is added will vary between
different operating systems, but will be familiar to those skilled
in the art. In circumstances where the installer software is
provided inflight, the software, once loaded into the passenger's
terminal, changes the dial-up networking settings as required and
starts the PPP service.
[0096] Internet client applications such as HTML browsers and
e-mail applications subsequently started by the passenger then
obtain Internet services from server 20 over the PPP service.
[0097] It will be appreciated that a user could manually carry out
the setting up of a new PPP connection, instead of obtaining and
running the installer software which automatically does this for
the user.
[0098] After the passenger disembarks from the aircraft after their
flight, the next time they attempt to connect to their
ISP/corporate server via a standard Public Switched Telephone
Network (PSTN) connection, for example, the relevant network
settings are still available on their computer. A dialer program
will automatically configure the passenger's computer for local
dial-up using a global roaming ISP dial up POP service.
[0099] Server 20 is configured to provide proxy Internet services
to the passengers' computers. For example, an HTTP request from a
passenger's computer for an HTML page is received by server 20,
which recovers the requested HTML page, if available, from its
cache. The HTML page is sent to the passenger's computer which need
not be aware that the page has not been sent directly from the
remote WWW site. Similarly, the server 20 responds to IMAP, POP3 or
SMTP requests from a passenger's computer as if it were the
passenger's normal ISP, by exchanging e-mail from the base station
via the server 20. Thus, the proxy configuration of the server 20
means that the passenger's computer appears to be connecting
directly to remote Internet services. The passenger informs the
server 20 of their e-mail server address, user id, password and
firewall details; this information may be automatically downloaded
from the passenger's computer to the server the first time the
passenger's e-mail system attempts to retrieve mail without any
additional or unique action on the part of the passenger.
[0100] With the above software and hardware arrangement, a data
rate up to the maximum speed of the passengers computer port is
possible, with a very large number of separate connections to the
server being possible. In practice, of course, there are typically
only 300 or so seats on an aircraft, and the server therefore only
ever needs a maximum of that many connections. In embodiments
making use of modem, serial port, USB and IEEE 1394 the provided
data rates are in the order of 56 kbps, 115.2 kbps, 12 Mbps and 400
Mbps respectively.
[0101] Furthermore, whilst the hardware and software connections
between the server and the passenger's computer have been described
in terms of PPP connections, it will be understood that Ethernet
connections are equally possible. Nonetheless, having understood
the function of the software operating on the passenger's computer,
the skilled person will have no difficulty in implementing a
similar program for Ethernet connection between that computer and
the server. In particular, the system registry settings of a
passenger's computer will need to be changed for the duration of
the flight to reflect the fact that the passenger's computer is to
be connected to a DNS gateway different to that which the passenger
would normally use, as well as the use of a server defined IP
address. The settings can be adjusted automatically by the
software, and then automatically reset when the flight terminates
and the passenger shuts down his computer.
[0102] In addition to acting as an SMTP/POP3/IMAP gateway for
sending and receiving e-mail messages to and from a passenger's
mail server on the ground, the server additionally acts as a local
WWW site. In particular, the server includes a large cache which
contains mirrors of a variety of WWW sites. These are loaded into
the cache either by remote connection, to be described below, or by
physically replacing the cache whilst the aircraft is at an
airport.
[0103] For the preferred server described above, a cache containing
a multitude of WWW pages can be stored, in addition to audio and
video data, to replicate a virtual world wide web environment.
Differential Management of Proxy Cache (DMPC) may be used. This
allows very large collections of WWW pages to be updated and
deleted on the basis of the changes to the code (HTML) within each
page, without having to reload all of each page when updating the
cache. When the cache is first loaded, DMPC also allows a
predetermined number of levels, such as three, within a particular
web site to be downloaded to the cache automatically. However, in
other embodiments a different number of levels are downloaded.
Where three layers are stored each separate site mirror stored in
the cache on the server contains the "home page," the first layer
of pages referred to in the home page, and the second layer of
pages referred to in the first layer of pages.
[0104] DMPC, or other processes, also removes any HTML code from
the WWW sites downloaded into the cache, where that code would
otherwise attempt to generate a hyperlink to a site that does not
exist on the cache. Thus, there is no possibility for a passenger
browsing the pages within the cache on board the aircraft to visit
Internet sites which have not been stored in the cache.
[0105] Although the passenger's computer is therefore only
accessing a "virtual" worldwide web, consisting of the pages of
information stored in the cache, the server provides the
information in a standard WWW form. Thus, each passenger can use
their normal web "browser" to access the information stored in the
cache as if they were accessing the original web site itself. As an
option, the cache may also contain a search engine to allow those
pages of interest to a passenger to be located.
[0106] In one preferred embodiment, the server provides a search
engine that references the URL of any pages contained on the
server. In the event that the exact page is not found the search
engine will conduct additional searching of the other URLs to
determine whether there are any that appear similar in meaning to
that one requested. Once obtained, the results of the search are
provided to the passenger for viewing. Results of searches that are
not matched may be used for updating the cache.
[0107] As previously mentioned, the cache can be updated in two
different ways. The quickest method is for the cache to be updated
directly from a cache drive which is brought on board the aircraft.
At major airports, a Terrestrial Control Unit or TCU will be
available for updating web-site content on a server. At any
particular time, a TCU will contain updated web content for the
sites that are contained on the server. When a aircraft arrives at
a particular airport, updating the web cache simply involves
transferring the updated information from the TCU to the server on
an aircraft via an appropriate medium. The server is switched on
and a physical connection is made between the cache drive
containing the data for updating and the cache within the server.
Preferably, the updating takes place via DMPC. The physical
connection can include physical replacement of the cache,
connection to a data loader, or via a direct connection to an
airport LAN.
[0108] An alternative method of updating the cache is from the TCU
closest to the arrival airport. In this embodiment this is achieved
by updating from the TCU via a wireless local area network (LAN)
once the aircraft has landed. Some airports now have LANs which
allow connection via wireless link such as "Gatelink" and high
speed LAN link cable. Thus, as the aircraft arrives at the airport,
the server can be configured to connect via this link to the
airport LAN. Once a connection between the server on board the
aircraft and the LAN hub has been established, the latter can
connect in turn to the closest TCU to obtain updates for the cache
within the server on board the aircraft. As with the method of
updating using a cache drive, the cache is updated using DMPC to
minimize updating time.
[0109] In some cases the links are other than those specified above
and the server is configured to utilize these links, as
required.
[0110] Another alternative, although more limited in application,
is to update the cache during flight.
[0111] The connection between server 20 and station 90 is best
illustrated in FIG. 1 and will now be described in more detail. As
passengers upon the aircraft compose and send e-mail messages,
those messages are passed to server 20 which stores them in a
dedicated region of the cache. Simultaneously, e-mail messages sent
from outside the aircraft and intended for passengers on board that
aircraft accrue in a memory within the station 90.
[0112] The transmission is carried between the server and the base
station using standard protocols (TCP/IP/PPP) or on a protocol
known as ANETP. This protocol has been developed to address the
perceived problems with wireless (satellite) connections between
the server on board the aircraft, and a base station. The data is
transferred in a compressed form using blocks, between two systems
that are linked via data connection.
[0113] Server 20 controls the connection to the station 90. At, for
example 15-minute intervals, the server connects to the base
station. The server provides the station 90 with a session ID and
the number of blocks it is about to transfer together with the size
size of these blocks. Simultaneously, the station 90 confirms with
server 20 the number and size of blocks to be transferred. The
block size determined by server 20 may be overruled by the base
station, which determines the speed and reliability of the
link.
[0114] Once confirmation is given, server 20 transfers block #1 to
the station 90. If this transfer is successful the base station
responds with an OK signal. This process continues until all blocks
have been sent, or the connection fails or times out. This same
process takes place for sending data from the base station to the
server, in one embodiment, simultaneously in both directions.
[0115] If the data stream is broken, the server restores the
connection from the next block after the last block successfully
acknowledged as received was sent.
[0116] Further details of the ANETP protocol may be found in
Appendix 1.
[0117] The INMARSAT telecommunications satellite is used in some
embodiments for transferring data. However, this only transfers
analog signals at 2,400 bits per second. However, low and medium
earth orbit communication satellites have recently been launched,
such as those offered by Globalstar and Iridium. These satellites
increase the available bandwidth for the server to base station
link.
[0118] The communications link remains active until the server has
delivered each of the messages waiting to station 90, and station
90 has also delivered each of its stored e-mail messages to server
20. When the server detects that the data transfers are complete,
it terminates the communications session with the base station.
From that point, any e-mail messages received at server 20 from the
passengers' computers are stored in the cache of server 20 until
the next connection to the base station is made. Similarly, e-mail
messages at station 90 are stored there until the next
connection.
[0119] Although communications have been described as being
connected intermittently, it will be appreciated that other
communications, specifically packet communications, which enable
the server 20 and station 90 to communicate without any additional
delay.
[0120] In addition to transferring e-mail message data, the
communications links (when connected) also transfers web site
updates during the flight. Because of the relatively low bandwidth
of the existing communications links, large scale updating of web
pages stored in the cache on server 20 is not practical. Small
amounts of information, perhaps relating to share prices, weather
updates and news flashes can be provided with a minimal amount of
data being transmitted. Thus, each time, a connection is made to
exchange e-mail messages, such updates can also be exchanged. The
ANETP protocol used for transferring data between the server and a
base station may dynamically assign the bandwidth available during
each connection.
[0121] Station 90 is arranged to connect to the mail servers of the
various passengers on board the aircraft. Typically, a normal
Internet connection 180 from network 150, as will be familiar to
those skilled in the art, is used. Certain mail servers, however,
allow only dial-up connections, and in that case it is preferable
to employ the Secure Socket Layer (SSL) protocol to allow
authentication of a base station by the mail server. Mail sent to
the passengers on board the aircraft will, of course, initially be
sent to the mailbox at the passenger's ISP/corporate mail server.
The system described above fetches the mail from the mailbox at the
passenger's mail server and forwards it to the passenger's computer
on the aircraft via station 90 and server 20. The system uses the
provided firewall information to gain access to mail servers
located behind a firewall. Likewise, messages sent from the
aircraft will travel first to the base station, before proceeding
on to their destination. In that case, there is no need for the
e-mail messages to be routed via the passenger's ISP/corporate mail
server. As will be explained in further detail in FIG. 3 below, the
SMTP protocol is used for forwarding e-mail messages from a base
station and it is this protocol which will decide the route to the
eventual destination.
[0122] As also shown in FIG. 1, station 90 connects via VPN 150 to
web content processor 190 for the purposes of updating the cache in
server 20. Once the updated pages are stored at station 90, they
are either be transferred via communications network 80.
[0123] In another embodiment of the invention more than one base
station is used for the intelligent management of e-mail
information between an aircraft and the Internet. Each base station
is identical in specification and also the information they hold.
This enables the aircraft to connect to any base station and find
the pertinent information for the aircraft ready for retrieval.
Each base station has connections to VPN 50, providing a means for
receiving connections from any airborne server, communicate with
other base stations/web content processors, and links to the
Internet for retrieving/sending customers' information.
[0124] The method by which e-mail messages are sent from
passenger's computers on the aircraft to their destination, and the
method of receipt of e-mail messages by the passengers' computers
on the aircraft from their respective ISP/corporate mail servers,
will now be described with reference to FIGS. 3 and 4.
[0125] There is a very high bandwidth connection possible between
each passenger's computer and server 20, and a potentially high
bandwidth between station 90 and its eventual destination or
passenger mail server. However, the bandwidth of the connection
between server 20 and station 90 is typically an order of magnitude
or more slower. The well-known SMTP protocol was developed for slow
but permanent connections between machines on networks. The
connection between server 20 and station 90 is, in contrast, both
slow and non-permanent. An important feature of the system is that
the connection time is relatively short, to minimize communications
costs. During a short connection time, it is important to recognize
that the negotiation or hand-shaking protocols and so forth will
take up a relatively large percentage of the total connection
time.
[0126] Server 20 receives e-mail messages from each passenger's
computer 40a, 40b and 40c. In FIG. 3, the SMTP protocol only is
shown. This is used because any computer with a browser will handle
this protocol. However, it will be understood that other protocols
such as HTTP are suitable depending upon the system requirements,
as will be familiar to those skilled in the art.
[0127] Messages in Internet mail format are stored in server 20.
When a connection is made between server 20 and station 90, the
e-mail messages are sent via a protocol which addresses the low
bandwidth and short communication time of the satellite connection.
Specifically, the protocol (ANETP) which carries the Internet
e-mail messages includes a number of compression systems to allow
for greater bandwidth and management of dropouts during the time in
which server 20 is connected to station 90. For example, depending
upon the size of files to be transferred, negotiations are carried
out. Once station 90 has received the e-mail messages, it forwards
them on to the various destinations using SMTP. The manner in which
the information is passed from the base station to the various
destinations is entirely standard and will be familiar to those
skilled in the art.
[0128] Referring now to FIG. 4, the method by which e-mail messages
are received from a passenger's ISP/corporate mail server to his or
her computer on board the aircraft is shown.
[0129] POP3 and IMAP are Internet standards for transferring mail
from mailboxes at customer mail server to that customer's computer.
The details of the these protocols will be well known to those
skilled in the art, and further details may be found in the RFCs.
While POP3 is acceptable for passing the messages to base station
90, it has several limitations which mean that its use is not
preferred for transfer of information between a base station and
the server. Specifically, POP3 does not allow message descriptions,
and attachments to e-mail messages (such as graphic images and the
like) are simply sent as encrypted, uncompressed text messages. The
attachments can therefore be extremely large and even on a standard
dial-up connection between a computer and an ISP, with a transfer
speed of 28.8 kbits per second, data transfer can take several
minutes. Thus, a separate protocol (ANETP) is used for transferring
mail between the base station and server 20. A method called
Intelligent Mail Management (IMM) is used to manage the collection
and delivery of e-mails including the management of any attachments
to the e-mails. The IMM protocol analyses e-mail messages to
identify the various components of the message. For example, if an
e-mail includes a text message and two attachments, the first
having a size of 4 Mb and the second having a size of 6 Mb, these
components are identified to server 20. It may be, of course,
impractical to send these very large attachments via the slow
communications links. Thus, the IMM method simply sends a summary
of the e-mail received at the base station from the passenger's
mail server to the server on board the aircraft, together with the
text part of the message. Once this has been received by server 20,
it is forwarded to the specified passenger, again using either the
HTTP protocol, the POP3 protocol or any other suitable
protocol.
[0130] When a passenger receives an e-mail message using this
system, he or she receives the text message and an indication of
any attachments to the original e-mail message. These attachments
are only sent to the passenger on board the aircraft upon the
passenger agreeing to pay a nominated fee. In one embodiment, the
passenger interacts with server 20 by utilizing a hyperlink in the
received message leading to a private interactive web page hosted
by server 20, providing an on-line means for the passenger to
control the delivery of attachments. Alternatively, the passenger
can defer delivery of large attachments until the passenger has
left the aircraft and established an alternative connection to the
relevant ISP/corporate mail server.
[0131] A potential problem arises when a passenger logs onto server
20, thus triggering the system to collect any waiting e-mail
messages from his mailbox at the ISP/corporate mail server, but
does not retrieve some messages subsequently collected by base
station 90 and stored in server 20 before leaving the flight.
Copies of e-mail retrieved by base station 90 may be retained at
the originating mail server; they are not necessarily deleted when
retrieved by base station 90. After the flight, the passenger will
connect to the originating mail server through whatever means and
these messages may still available for download. Some mail clients
will detect those messages that have been already received and will
automatically delete the duplicates from the originating mail
server without necessarily downloading them. In one embodiment,
e-mail that is not delivered to the passenger is resent to or
retained by base station 90 and then subsequently resent to the
passenger's e-mail account as a new Internet e-mail message. Base
station 90 can format the resent message to appear virtually
identical to the original message without regard to mail server
capabilities. In a preferred embodiment, server 20 informs base
station 90 which messages have been delivered to terminals 40a, 40B
and 40C, and base station 90 then contacts ISP/corporate 110a, 110b
and 110c mail servers and deletes those messages confirmed to have
been delivered from the appropriate mail servers.
[0132] Server 20 and base station 90 coordinate the registration of
passengers such that e-mail is retrieved optimally for the duration
of a flight. By monitoring aircraft system parameters such as
passenger doors open/closed and whether the aircraft is airborne or
on the ground, server 20 determines the appropriate time for base
station 90 to cease retrieval of e-mail for that set of passengers
on that particular flight. Base station 90 incorporates additional
monitors to recover from the loss of communications with a
particular server 20. Server 20 can detect unusual events, such as
cancelling a flight without leaving the gate, return to gate
without taking off, and holding short of the destination gate for
extended periods of time, and provide the optimum level of service
for the particular situation. For example, e-mail retrieval from
base station 90 may cease when the doors open at the destination
gate, while server 20 is obliged to provide any e-mail already
retrieved from base station 90 to a passenger's laptop for as long
a period of time that is practical, for example 20 minutes after
doors open.
[0133] The operating system of the preferred server also
continually monitors all of the primary services provided by the
server. If errors occur then the system automatically re-boots.
However, remote diagnosis of faults on the server is also possible
using the communications link with the base station 90. SNMP is
used for network monitoring.
[0134] The aircraft network 50 provides additional advantages.
Passengers may communicate with one another using the network, or
with airline crew to request assistance, for example. The server,
in some embodiments is also configured to provide audio and video
images to the passengers. Currently, some aircraft provide a screen
(in the back of the seat in front of the passenger), and audio
sockets in that passenger's armrest. A relatively small selection
of audio and/or video programs are selectable by the passenger.
Using the present system, provided that a passenger has a portable
computer with audio/video capabilities, that is, a sound card and
MPEG driver, then a very large quantity of audio/video
entertainment can be provided. The very high data transfer rate
possible on board the aircraft, when data does not have to be
received from the ground, and the large amount of storage space on
the server, permits, for example, MPEG movies to be viewed or games
to be played.
[0135] Another embodiment of the invention is illustrated in FIG. 5
and FIG. 6. More particularly, in this embodiment, use is made of a
plurality of like spaced apart base stations. For ease of
illustration only a second base station 120 is shown. It will be
appreciated, however, that in this embodiment three such stations
are used. In other embodiments more than three base stations are
used.
[0136] Rather than communicating with any one of the base stations,
server 20 communicates with that base station to which it is
closest to at the time. The technique by which the aircraft
connects to a base station, and in particular how hand-over between
a first base station 90 and a second base station 120 takes place,
will now be described in more detail with reference to FIG. 5 and
FIG. 6. The planet is divided up into regions 400, 410 with a
region of overlap 420 between them. FIG. 4 only shows two such base
stations 90, 120 and their respective cells 400, 410. However, in
practice, a number of base stations will be provided around the
planet at suitable locations. For example, base stations may be
provided in Western Europe, North America, South America, South
East Asia, Southern Africa and Australia. The size of each cell
will, of course, depend upon the total number of base stations
provided, so that the main airline routes are covered. In one
preferred embodiment of the invention only three base stations are
utilized, one in the UK, one in the USA and one in Australia.
[0137] An aircraft flying from London to New York will connect over
the initial part of its flight to the first base station 90
located, for example, in the Republic of Ireland. Station 90 is
used when the aircraft is stationary at the point of embarkation.
While the aircraft is being cleaned and refueled, the wireless
connection to the airport LAN is made, or the cache drive is
supplied, to update the cache within server 20. Once the aircraft
leaves the airport in London, all communications are made via
communications service provider networks 80 to base station 90. At
position A shown in FIG. 6, for example, the aircraft is still
within the first cell 400 and communicates solely with station 90.
The aircraft is able to track its own position using aircraft
system 130. Each time the aircraft connects to station 90, in
addition to exchanging data carrying e-mail messages and cache
updates, it also informs station 90 of its position.
[0138] Each base station is pre-programmed with its coverage area.
Thus, when the aircraft enters the transition area between two
cells, station 90 commands server 20 to contact station 120 for
subsequent serves upon the completion of the next data exchange
with server 20. Station 90 then contacts station 120 via VPN 150
and provides the necessary information for station 120 to continue
to provide service.
[0139] The aircraft initiates communications and continues to
communicate with station 120, which now carries out the various
functions previously carried by station 90, such as downloading
information from various Internet sites so that the cache in server
20 can be updated, and connecting to the passenger's mail server to
retrieve e-mail messages. The second base station preferably
provides different information to the first base station. For
example, when the cache is updated during the flight, news, weather
and so forth for the geographical area surrounding station 120 is
provided instead. Passengers travelling from London to New York can
accordingly receive both up-to-date and relevant information
throughout the flight.
[0140] Under some circumstances, it is possible server 20 will
inadvertently contact the wrong base station. While server 20
should retain necessary information in non volatile memory to
recover gracefully from a reset condition, all base stations will
respond to server 20 with the necessary information to contact the
correct base station, using VPN 150. In one embodiment, certain
passenger configuration information is retained at the base station
to enable server 20 to recover from a reset condition without
interrupting service or necessitating all passengers re-register
for service.
[0141] Aircraft network 50 provides a set of connection points 30
that provide a means to communicate between server 20 and each
passenger terminal 40a, 40b, 40c. A typical terminal may have one
or more of the following interfaces available:
[0142] 1. Modem
[0143] 2. RS232 Serial Port
[0144] 3. Universal Serial Bus (USB)
[0145] 4. IEEE 1394
[0146] 5. Ethernet Port
[0147] The aircraft network may support one or more of the above
interfaces. Exemplary characteristics for such networks are
described below with reference to FIGS. 7, 8 and 9. More
particularly, FIG. 7 illustrates a modem network interface that
allows the passenger to connect their modem to a telephone mounted
such that access is available from their seat. In many cases, only
one phone is available for each three passengers. It is typical
that a dedicated phone is available to passengers flying in premium
seats.
[0148] Airborne telephone networks generally follow the guidance of
ARINC 746, "Cabin Communications Systems," and ARINC 628, "Cabin
Equipment Interfaces."
[0149] A Cabin Telecommunications Unit (CTU) 65 provides a
telephone switching capability between the Cabin Distribution
System (CDS) 67 (which provides the telephones in the cabin) and
the radios 60 that provide air ground telephone service. The
interface from the CDS 67 to the CTU 65 is described in ARINC 746,
attachment 17, although many configurations are not completely
compliant with this definition. The interface from the CTU 65 to
the air ground radios 60 is described in ARINC 746, attachment 11.
Most CTUs and radios comply with this specification, and are
interchangeable.
[0150] Network 50 provides an interface to the CTU 65 such that
server 20 appears to be an air ground radio to the CTU 65. The CTU
65 routes calls to server 20 in a manner identical to the way the
CTU 65 routes telephone calls to the other air ground radios
60.
[0151] The handset 30 generally provides an RJ11 jack to provide a
two wire interface to the passenger modem. The passenger configures
their PPP dial up networking to call a special phone number
allocated for this service. The passenger connects their terminal
40a to the telephone handset 30 and initiates the telephone call.
The CTU 65 routes this call request to server 20 based on the phone
number that is being dialed by the passenger terminal 40a (and does
not route the call to the air ground radios 60).
[0152] The server 20 terminates each call request into an internal
modem bank. This allows the passenger modem and the server modem to
communicate at data rates as high as 56 kbps using an existing
cabin telephone system, given minimal configuration changes to the
CTU.
[0153] An alternative interface is an RS232 port, which is
illustrated in FIG. 8. Such an interface is available on many
passenger terminals and can provide data rates as high as 115 kbps.
Accordingly, the aircraft network 50 shown in FIG. 8 provides a
jack 30 which allows the passenger to connect their RS232 port from
their seat. The jack 30 is connected to a dedicated Cabin
Distribution Network 69, which provides a communications path to
server 20. The passenger terminal 40a is configured to utilize the
serial port and establishes a PPP connection with server 20.
[0154] Some passenger terminals will support a USB connection, with
data rates as high 12 Mbps. The aircraft network 50 shown in FIG. 8
provides a jack 30, which allows the passenger to connect their USB
port from their seat. The jack 30 is connected to a dedicated Cabin
Distribution Network 69, which provides a communications path to
server 20. The passenger terminal 40a is configured to utilize the
USB port and establishes a PPP connection with server 20.
[0155] Some passenger terminals will support an IEEE 1394
connection, with data rates as high 400 Mbps. The aircraft network
50 shown in FIG. 8 provides a jack 30, which allows the passenger
to connect their IEEE 1394 port from their seat. The jack 30 is
connected to a dedicated Cabin Distribution Network 69, which
provides a communications path to server 20. The passenger terminal
40a is configured to utilize the IEEE 1394 port and establishes a
PPP connection with server 20.
[0156] Some passenger terminals will support an Ethernet interface,
with data rates as high as 100 Mbps. The passenger terminal can be
connected to the aircraft network as shown in FIG. 9. Typically,
the interface uses an RJ45 jack connected into an Ethernet Hub. The
Hub(s) provide IP networking services between the passenger
terminal 40a and the server 20. This aircraft network is well known
to one familiar in the art. In one embodiment, a router is provided
between the passenger terminal Ethernet port and the Ethernet Hub
to allow use of a passenger terminal 40a fixed IP address and the
server 20 assigned IP address.
[0157] The various protocols referred to in this specification,
unless otherwise indicated, are all industry standards. Full
details of these standards may be obtained from various sources as
will be known by those skilled in the art.
[0158] Preferred embodiments of the invention offer many and varied
advantages and improvements over the prior art systems. By way of
example, at least the following advantages are achieved:
[0159] 1. A plurality of users are cost effectively bundled
together for communication with a single ground station;
[0160] 2. e-mail being sent to the user during the flight is stored
on the onboard server notwithstanding that the actual user is not
logged onto that server at the time including users whose mail
servers are behind a corporate firewall
[0161] 3. Use can be made of any ISP/corporate mail server and any
communication protocol;
[0162] 4. An e-mail message to the user will include a hypertext
link for any attachments. Should the user wish to access the
attachments they will be linked to a private web page which allows
retrieval of that attachment;
[0163] 5. The homepages on the onboard server will masquerade as
the actual homepages;
[0164] 6. Differential updating of onboard web pages; and
[0165] 7. The user's e-mail name and password are captured and
utilized such that the user does not have to have these re-entered
during the establishment of the intermittent communication between
the base station and the onboard server.
[0166] Although the invention has been described with reference to
a specific example it will be appreciated by those skilled in the
art that it may be embodied in many other forms.
* * * * *