Communication system with communication route retrieval and selection function

US006483835B1

62> United States Patent (10) Patent N0.: US 6,483,835 B1

Tanigawa et al. (45) Date of Patent: Nov. 19, 2002

(54) COMMUNICATION SYSTEM WITH “RSVP: A New Resource ReSerVation Protocol”, IEEE COMMUNICATION ROUTE RETRIEVAL Network ('93/9).

AND SELECTION FUNCTION IEEE Network, Jan./Feb. 1998, “Real-Time Voice Over

(75) Inventors, Keikn Tnnignwn, Kawasaki (JP); Packet-Switched Networks”, T. Kostas et al., pp., 18-26. Susumu Mat5ul> Maonloa (JP); Kojl IEEE Network, Sep. 1993, “RSVP: A New Resource ReerT5ukada> Tokyo (JP); Tohru Ho5nl> Vation Protocol”, L. Zhang et al., pp. 8-18. Yokohama (JP) Proceedings of the IEEE, vol. 61, No. 3, Mar. 1973, “The (73) Assignee: Hitachi, Ltd., Tokyo (JP) VllerblAlgoTllnn1”> G~ FoTneY> P~ 2o8_278~ ( * ) Notice, Subject to any disclaimer, the term of this IEEE Transactions on Communications, vol. Com—22, No.

5, May 1974, “Adaptive Maximum—Likelihood Receiver for Carrier—Modulated Data—Transmission Systems”, G. Ungerboeck, pp. 624-636.

patent is extended or adjusted under 35
U.S.C. 154(b) by 0 days.

(21) App1_ NO_; ()9/092,941 IEEE Signal Processing Magazine, Sep. 1995, “Implement' th V't b' Al 'th ”, H. L , . 42-52. (22) Filed: Jun. 8, 1998 mg e 1 er 1 gon m Ou pp

IEEE Communications Magazine, May 1991, High—Speed

(30) Forelgn Applloatlon Prlorlty Data Parallel Viterbi Decoding: Algorithm and VLSI-ArchitecJun. 12, 1997 (JP) ........................................... .. 9-154737 lure G~ Feowels et al» PP~ 46_55~ (51) Int. Cl.7 .............................................. .. H04L 12/56 4 Cited by examiner (52) U.S. Cl. ................................. .. 370/395.21; 370/401 (58) Field of Search ............................... .. 370/230, 231,

370/232, 233, 234, 235, 236, 248, 252, Primary Examiner—Kwang Bin Yao 253, 254, 255, 256, 352, 353, 354, 355, (74) Attorney, Agent, 0r Firm—Mattingly, Stanger & 356, 401, 402, 403, 404, 405, 410, 395.1, Malur, P.C. 395.2, 395.21, 395.4, 395.41, 395.52

(57) ABSTRACT

(56) References Clted A gateway (GW) for relaying a communication between a U_S_ PATENT DOCUMENTS public telephfonhe nejgvvork gnd a I"OLlI1I11(g server fognnlanagiing

use status o t e an a networ are provi e on t e

5,637,167 A * 11/ 1997 Benin el al~ ~~~~~~~~~~~~~~ ~~ 37o/254 internet. When a connection request is received, the GW 5>732>o78 2 : €/ émnego """""" " 337710/235? issues a request to retrieve a route in which the costs are A * Q1999 Kilesanij 376/331 minimum and a necessary bandwidth can be reserved. The 5’94O’372 A * 8/1999 Benin et ,n_ __ 370/238 routing server retrieves the route of the minimum costs using 5’948’069 A 4 9/1999 Kiwi et a1_ __ 709/240 the bandwidth reservation status of the internet and the 6:078:582 A 4 6/2000 Curry et a1_ _ 370/356 partner’s telephone number and notifies the request issued 6,154,444 A * 11/2000 Masuo et al. 370/225 GW of the address of the partner GW. The costs at that time 6,157,648 A * 12/2000 Voit et al. ................. .. 370/401 point may be notified to the user and the user selects whether

the communication is performed or not. By managing the OTHER PUBLICATIONS current connection information established by each GW, if a

“Resource Reservation Protocol (RSVP) Ven 1, Functional necessary bandwidth cannot be reserved, an audio compres

Specification”, RFC 2205, Sep. 97. 51°“ lane may be ehanged~
“Real Time Voice Over Packet—Switched Networks” (‘98/
2). 14 Claims, 21 Drawing Sheets

D/A CONVERTING
UNIT 339

RETRIEVING UNIT 01 306

3
I I I I
CONNECTION CONNECTION \ COMMUNICATION CONNECTION ‘

REQUEST ESTABLISHING RELAY END
RECEPTION UNIT PROCESSING PROCESSING
PROCESSING UNIT UNIT

GW103