Dynamic Cellular Cognitive System

• US 20090215457A1
• Filed: 02/25/2009
• Published: 08/27/2009
• Est. Priority Date: 02/25/2008
• Status: Active Grant

• Current Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Wang, Ying, Bostian, Charles W.
• Granted Patent: US 8,094,610 B2
• Time in Patent Office: Days
• US Class Current: 455/435.100
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

High quality communications among a diverse set of cognitive radio (CR) nodes is permitted while minimizing interference to primary and other secondary users by employing Dynamic Spectrum Access (DSA) in a Dynamic Cellular Cognitive System (DCCS). Diverse device types interoperate, cooperate, and communicate with high spectrum efficiency and do not require infrastructure to form the network. The dynamic cellular cognitive system can expand to a wider geographical distribution via linking to existing infrastructure.

Claims

1. A dynamic cellular-based cognitive system, comprising:

a plurality of cognitive radios each of which is configured to function as a picocell cognitive node (PCN) or a cognitive mobile terminal (CMT) depending on whether said cognitive radio senses the existence of a PCN,

where a cognitive radio either establishes itself as a PCN if no PCN is sensed upon sending a registration request or registers itself as a CMT with a particular PCN upon receiving a response to a registration request;

at least a first group of cognitive radios function as PCNs and at least a second group of cognitive radios function as CMTs,

each PCN within said first group provides spectrum management within its respective cell, and each PCN within said first group managing inter-cell communications between one or more PCNs within said first group, and

each CMT with said second group function cognitively, and are configured for both direct intra-cell communications with another CMT or indirect intra-cell communications using the PCN to which it is registered.

2. The dynamic cellular-based cognitive system of claim 1 further comprising one or more radios, and wherein each PCN assigns communication channels among one or more narrow band modulations selected from the group consisting of MPSK, FM, AM, and FSK or OFDM wideband communication for intra-cell communications with one or more CMTs or one or more radios within its cell.

3. The dynamic cellular-based cognitive system of claim 2 wherein said one or more radios include legacy radios.

4. The dynamic cellular-based cognitive system of claim 1 wherein each PCN manages spectrum access within its cell dynamically according to a channel selection strategy.

5. The dynamic cellular-based cognitive system of claim 1 wherein each PCN manages spectrum access within its cell dynamically in combination with one or more adjacent PCNs.

6. The dynamic cellular-based cognitive system of claim 1 wherein each CMT or other node saves information pertaining to a detected energy from its PCN for a specified amount of time, and, if a PCN for a cell stops functioning, the information is used to identify an alternative PCN for said cell which is the closest to said PCN which stops functioning.

7. The dynamic cellular-based cognitive system of claim 1 wherein one or more of PCNs and CMTs use energy detection to determine existence of a signal on a channel.

8. The dynamic cellular-based cognitive system of claim 7, wherein each PCN analyzes channel records for nodes in its cell on the duration of occupation each channel basis by primary and secondary users.

9. The dynamic cellular-based cognitive system of claim 7, where in each PCN detects energy on each channel sequentially and sends and receives command messages to manage channels.

10. The dynamic cellular-based cognitive system of claim 7 wherein a detection result will be used by a PCN for channel statistic information analysis to predict an optimal channel to allocate when said PCN is being requested for a channel assuming primary users or other secondary users outside of a group is an exponential distribution.

11. The dynamic cellular-based cognitive system of claim 1, wherein each PCN and CMT control collision avoidance by permitting transmissions on channels where energy is not detected.

12. The dynamic cellular-based cognitive system of claim 11, wherein each of a plurality of potential PCNs (PPCN) that is transformed to a PCN will listen a short duration for a collision message and sending out a transmission if no collision message is received from others using a same channel which is the available channel with lowest frequency and which is dynamically decided during the transmission.

13. The dynamic cellular-based cognitive system of claim 11, where each PCN waits for acknowledge message after sending respond message when a request message on said channel is detected.

14. The dynamic cellular-based cognitive system of claim 11, where each PCN switches to a next channel when an acknowledge message on a channel is detected, or when a waiting time for said acknowledge message exceeds certain threshold.

15. The dynamic cellular-based cognitive system of claim 11, where PCN eliminates from use a channel where energy is detected but no request or acknowledge message is detected.

16. The dynamic cellular-based cognitive system of claim 11, where CMT sends request message based on demand when no energy is detected on a channel.

17. The dynamic cellular-based cognitive system of claim 11, where CMT randomly choose another channel for energy detection if energy is detected on said channel and no respond message is detected.

18. The dynamic cellular-based cognitive system of claim 11, wherein a cognitive radio establishes itself as a CMT switched to PCN if a repeat receiving request message is received from another CMT for a specified time duration.

19. A bridge connecting a break in an Internet Protocol network, comprising a dynamic cellular-based cognitive system comprising:

a plurality of cognitive radios each of which is configured to function as a picocell cognitive node (PCN) or a cognitive mobile terminal (CMT) depending on whether said cognitive radio senses the existence of a PCN,

where a cognitive radio either establishes itself as a PCN if no PCN is sensed upon sending a registration request or registers itself as a CMT with a particular PCN upon receiving a response to a registration request;

at least a first group of cognitive radios function as PCNs and at least a second group of cognitive radios function as CMTs,

each PCN within said first group provides spectrum management within its respective cell, and each PCN within said first group managing inter-cell communications between one or more PCNs within said first group, and where at least one PCN of said first group is in communication with said Internet Protocol network, and

each CMT with said second group function cognitively, and are configured for both direct intra-cell communications with another CMT or indirect intra-cell communications using the PCN to which it is registered.

20. The bridge of claim 19 wherein a CMT of said second group becomes a PCN of said first group when said CMT is able to communicate with said Internet Protocol network directly.