Secure communication hub and method of secure data communication

• US 6,240,074 B1
• Filed: 02/19/1998
• Issued: 05/29/2001
• Est. Priority Date: 02/19/1998
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Chandos, Ronald V., Harrison, David M., Worger, William R.
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/025,808
• Time in Patent Office: 1,195 Days
• Field of Search: 370/321, 370/316, 370/319, 370/326, 370/524, 370/535, 370/536, 455/428, 455/432, 455/429, 455/430, 455/454, 455/427
• US Class Current: 370/321
• CPC Class Codes: H04B 7/18565 Arrangements for preventing unauthorised access or for providing user protection arrangements for secret or secure communication H04L9/00

Abstract

A secure communication hub (10) relays local communications between low probability of intercept (LPI) user radio equipment (68) and provides a secure interface with a command center (58) through a non-geostationary commercial satellite communication system. The secure communication hub (10) includes different radio interface units (12) for communicating different data formats with the (LPI) user radio equipment (68). Encryption and decryption circuitry (18) provides for different security levels and different keys for the (LPI) user radio equipment. Links with the satellite system are secured using encryption.

Claims

1. A secure communication hub for routing communications among local user radio equipment, and securely routing communications with a remote command center using a satellite communication system, the secure communication hub comprising:

a plurality of radio interface units, each for communicating with select ones of the local user radio equipment, wherein at least some of the radio interface units communicate with the local radio equipment using a low-probability of detection format;

a router coupled with each radio interface unit;

a format converter coupled to the router;

a satellite transceiver for communicating with satellites of the satellite communication system;

data encryption/decryption circuitry coupled between the satellite transceiver and the router for providing encrypted data packets to the satellite transceiver and providing decrypted data packets to the router;

a routing controller coupled to the router for controlling routing of communications among the plurality of radio interface units, and routing communications between the satellite transceiver and the radio interface units,

wherein when data destined for the remote command center is received from one of the local user radio equipment, the format converter performs a format conversion on said data to create packetized data suitable for said satellite communication system, the routing controller adds routing instructions to said data to identify said command center as a destination for said data, the data encryption/decryption circuitry encrypts said data on per-packet basis, and the satellite transceiver transmits said data in packetized form for routing through the satellite communication system to the command center.

2. A secure communication hub as claimed in claim 1 wherein the satellite communication system includes non-geostationary satellites in low-earth orbit, and wherein the secure communication hub includes a directional satellite antenna coupled with the satellite transceiver, the directional satellite antenna having means for tracking the non-geostationary satellites and communicating information from the satellite transceiver, and wherein said non-geostationary satellites communicate directly with adjacent non-geostationary satellites of said satellite communication system with cross-links, whereby said data destined for the remote command center is routed among said non-geostationary satellites over said cross-links, said data being in packetized form and being routed along with commercial voice and data packets destined for the public switched telephone system.

3. A secure communication hub as claimed in claim 2 wherein when data destined for one of the local user radio equipment is received from the command center, the data encryption/decryption circuitry decrypts said data on a per-packet basis, the format converter performs a format conversion on said data to said low-probability of detection format, and the routing controller determines which of the radio interface units to route said data to based on routing instructions received with said data.

4. A secure communication hub as claimed in claim 2 wherein the secure communication hub communicates with a plurality of types of said local user radio equipment communicating with different modulation formats, and wherein the secure communication hub includes a radio interface unit for each type of said local user radio equipment.

5. A secure communication hub as claimed in claim 2 wherein the plurality of radio interface units include means for communicating with different types of user radio equipment, and wherein the different types of radio interface units receive and transmit information in differing data forms with corresponding user radio equipment, some of the user radio equipment providing digital packetized data, some of the user radio equipment providing data in analog form, and wherein the different types of radio interface units include at least a first radio interface unit for the digital packetized data, and a second radio interface unit for the data in analog form.

6. A secure communication hub as claimed in claim 2 wherein the plurality of radio interface units communicate with different types of user radio equipment, and wherein the different types of radio interface units receive and transmit information in differing data forms with corresponding user radio equipment, wherein some of the user radio equipment provide digital packetized data in first and second data formats, the different types of radio interface units including first and second radio interface units for respectively, communicating the first and second data formats.

7. A secure communication hub as claimed in claim 2 further comprising a local antenna coupled with each of the radio interface units, the local antenna for communicating signals with the local user radio equipment.

8. A secure communication hub as claimed in claim 7 wherein the local antenna is an omni-directional antenna.

9. A secure communication hub as claimed in claim 7 wherein the local antenna is a phased array antenna that provides directional signals corresponding with directions of the user radio equipment.

10. A secure communication hub as claimed in claim 2 wherein the secure communication hub is located on a movable ground station.

11. A secure communication hub as claimed in claim 2 wherein the secure communication hub is located in an aircraft.

12. A secure communication hub as claimed in claim 1 wherein encrypted data is received from a communication satellite through the satellite transceiver, and wherein the data encryption/decryption circuitry decrypts the encrypted data in accordance with a type of user radio equipment the encrypted data is intended, and

wherein the data encryption/decryption circuitry encrypts data received from the user radio equipment for transmission to the communication satellite, the encryption being in accordance the type of user radio equipment.

13. A secure communication hub as claimed in claim 2 wherein the radio interface units communicate with local user radio equipment, the user radio equipment being low probability of detection (LPD) user radio equipment providing data packets in an LPD modulation format.

14. A secure communication hub as claimed in claim 2 wherein at least one of the radio interface units include means for communicating spread spectrum signals with the user radio equipment.

15. A secure communication hub as claimed in claim 14 wherein at least one of the radio interface units include means for communicating code division multiple access (CDMA) signals with the local user radio equipment.

16. A secure communication hub as claimed in claim 2 wherein each of the radio interface units converts RF signals from the local user radio equipment to corresponding baseband signals, and wherein each of the radio interface units converts baseband signals to RF signals for transmission to the local user radio equipment.