Satellite-based communications system having an on-board internet web proxy cache

• US 6,697,850 B1
• Filed: 05/09/2000
• Issued: 02/24/2004
• Est. Priority Date: 05/09/2000
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Saunders, Oliver W.
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US09/567,853
• Time in Patent Office: 1,386 Days
• Field of Search: 709/219, 709/231, 709/200, 709/217, 370/464
• US Class Current: 709/219
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method and system for communicating internet data in a satellite-based communications system. A request for a selected web page is transmitted from either a standard terminal or an enhanced terminal to the satellite. The satellite initially determines whether the transmission came from a standard user or an enhanced terminal. If the request was from a standard terminal, the satellite relays the request for the web page directly to the ground station, which retrieves the requested web page from a local cache or the internet, and transmits the requested web page to the satellite, where the satellite in turn retransmits it to the user terminal. If the original request was transmitted from an enhanced terminal, then the satellite determines whether or not it already has a copy of the requested web page in its on-board memory cache. If the satellite has a copy in its memory cache, the requested web page is retrieved from its memory cache and transmitted to the enhanced terminal. If the satellite does not have a copy of the requested web page, it requests the page from the ground station if the same fashion as with the standard terminal.

Claims

1. A method for communicating Internet data in a satellite-based communications system comprising:

transmitting a request for a selected web page from a ground terminal to a satellite;

determining, on the satellite, whether the satellite already has a copy of the requested web page in satellite-located memory;

if the satellite has a copy of the requested web page in satellite-located memory, retrieving the requested web page from satellite-located memory and transmitting the web page from the satellite to the ground terminal; and

if the satellite does not have a copy of the requested web page, requesting, by the satellite, the web page from a ground station interconnected with the Internet, receiving the requested web page from the ground station, and transmitting the requested web page to the ground terminal.

2. The method according to claim 1, including transmitting on a first link web pages retrieved from satellite-located memory, and transmitting on a second link web pages obtained as a result of a satellite to ground station request.

3. The method according to claim 1 further comprising tracking on said satellite the frequency of requests for individual web pages, and periodically requesting from said ground station those web pages having the highest frequency of requests.

4. The method according to claim 3 further comprising storing those web pages having the highest frequency of requests in said satellite-located memory.

5. The method according to claim 1 further including periodically refreshing the web pages stored in the satellite-located memory.

6. A method for communicating internet data in a satellite-based communications system comprising:

transmitting a request for a selected web page from a ground terminal to a satellite;

determining, on the satellite, whether the satellite already has a copy of the requested web page in satellite-located memory;

if the satellite has a copy of the requested web page in satellite-located memory, retrieving the requested web page from satellite-located memory and transmitting the web page from the satellite to the around terminal

if the satellite does not have a copy of the requested web page, requesting, by the satellite, the web page from a ground station interconnected with the Internet, receiving the requested web page from the around station, and transmitting the requested web page to the ground terminal;

transmitting on a first link web pages retrieved from satellite-located memory, and transmitting on a second link web pages obtained as a result of a satellite to ground station request; and

determining at said satellite the capability of said ground terminal to receive web pages on both said first and second links, and if the ground terminal lacks the capability to receive on both links, then requesting web pages from the ground station notwithstanding the existence of the requested web page in satellite-located memory.

7. A method for communicating Internet data in a satellite-based communications system of the type Including a satellite having a memory cache therein containing selected web pages, a user terminal capable of receiving one type of data transmission, an enhanced terminal capable of receiving at least two types of data transmissions, and a ground station interconnected with the Internet, said method comprising:

transmitting a request for a selected web page from one of said user terminal and said enhanced terminal to said satellite;

determining, on the satellite, the type of terminal from which the request was transmitted;

in the event the request was transmitted from an enhanced terminal, then;

determining whether the satellite already has a copy of the requested web page in the memory cache;

then

if the satellite has a copy of the requested web page in the memory cache, retrieving the requested web page from the memory cache and transmitting the web page from the satellite to the enhanced terminal; and

if the satellite does not have a copy of the requested web page, requesting the web page from the ground station, receiving the requested web page from the ground station, and transmitting the requested web page to the enhanced terminal; and

in the event the request was transmitted from a user terminal, then requesting the web page from the ground station, receiving the requested web page from the ground station, and transmitting the requested web page to the user terminal.

8. The method according to claim 7 further including periodically refreshing the web pages stored in the memory cache.

9. The method according to claim 7 further including tracking the frequency of requests for individual web pages, periodically requesting from the ground station those web pages requested the most frequently, and storing those most frequently requested web pages in the memory cache.

10. A satellite-based communications system comprising:

a satellite located in space including a first processor and a memory storage device therein, said memory storage device containing data concerning the content of a plurality of Internet web pages, said satellite further including antenna means for transmitting first and second streams of RF data and receiving RF data;

an enhanced terminal located on earth and comprising;

an enhanced terminal monitor for displaying web pages;

enhanced terminal receiving means for receiving RF data from said satellite antenna, said enhanced terminal receiving means capable of receiving first and second RF data streams from said satellite antenna means;

enhanced terminal processing means for translating said received RF data into web pages for display on said enhanced terminal monitor;

enhanced terminal request generation means for requesting data to enable the display of selected web pages; and

enhanced terminal transmission means for transmitting said requests for data to said satellite; and

a ground station located on earth interconnected to the internet and including means for transmitting RF data to and receiving RF data from, said satellite, said ground station receiving requests for selected web pages from said satellite, connecting to the requested web pages on the intermet, and transmitting data concerning the content of the requested web pages to said satellite;

said first processor processing requests for data received from said enhanced terminal request generation means to determine if the memory storage device contains data for the requested web page; and

,

if so, withdraws such requested web page data from the memory storage device and transmits such requested web page data as said first data stream to said enhanced terminal; and

if not, transmits the request for data to said ground station, and upon receipt of said requested web page data from said ground station, retransmits such requested web page data as said second data stream to said enhanced terminal.

11. The communications system according to claim 10 further comprising:

a user terminal located on earth comprising;

a user terminal monitor for displaying web pages;

user terminal receiving means for receiving RF data transmitted from said satellite antenna means;

user terminal processing means for translating said received RF data into web pages for display on said user terminal monitor;

user terminal request generation means for requesting data to enable the display of selected web pages; and

user terminal transmission means for transmitting said requests for data to said satellite.