(12) United States Patent
(10) Patent No.: US 6,580,700 B1
Pinard et al. (45) Date of Patent: *Jun. 17, 2003 (54) DATA RATE ALGORITHMS FOR USE IN (56) References Cited WIRELESS LOCAL AREA NETWORKS Us PATENT DOCUMENTS (75) Inventors: Patrick Pinard, Santa Clara, CA (US); 5,448,569 A * 9/1995 Huang et al. ............. .. 370/332 Dgan Kawaguchi, San JQSQ, 5,465,401 A 11/1995 ThOII1pSOl1 .... .. 455/89 5,483,669 A * 1/1996 Barnett et al. 455/33.2 (73) Assignee: Symbol Technologies, Inc., Holtsville, 2 * gltlhlany et 411 ~ 45357/S/76/11 NY , , art Cit ......... .. ( ) 5,568,513 A 10/1996 c16116161. ............... .. 375/224 ~ ~ ~ ~ ~ 5 584 048 A 12 1996 W' k ............... .. 455 38.3 ( * ) Notice: Subject to any disclaimer, the term of this 5’63O’2O7 A 41997 Gilgicnzgeal 45454 1 patent is extended or adjusted under 35 5:640:414 A * 6/1997 Blakeney’ 1.1 375/260 U59 154(1)) W0 days 5,649,289 A 7/1997 w66g 6161. ............. .. 455/31.3 5,793,303 A 8/1998 Koga .................. .. 340/825.44 This patent is subject to a terminal dis- 5,815,811 A 9/1998 P166111 6161. ............. .. 455/434 claimer. 5,896,561 A * 4/1999 Schrader et al. . . 455/67.1 5,915,214 A * 6/1999 Reece et al. ..... .. 455/406 _ 5,920,821 A * 7/1999 Seazholtz et al. ......... .. 455/466 (21) APP1" NO" 09/222426 5,960,335 A * 9/1999 U16616616 6161. ..... .. 455/226.2 (22) Filed; Dec_ 29, 1998 5,987,062 A * 11/1999 Engwer et al. ........... .. 375/225 6,005,853 A * 12/1999 Wang et al. .............. .. 370/332 Related U.S. Application Data * ¢i16d by examiner . . . . . P ' E ' —D T (63) Continuation-in-part of application No. 08/747,034, filed on I Ex;lZ17Z.1j;r_Ti?g}I (glam Nov. 8, 1996, now Pat. No. 6,002,918, which is a continu- ' ation-in-part of application No. 08/549,051, filed on Oct. 27, (57) ABSTRACT 1995, now Pat. No. 5,815,811. (51) Int. Cl.7 ................................................ .. H04Q 7/00 Acommtmlcanons netwofk Compnsmg a_W1reTeSS local area network includes a plurality of access points connected to a (52) U.s. Cl. ..................... .. 370/332, 370/252, 370/343, 1 370/543, 455/432, 455/434, 455/436 . g g. . least one access point. The mobile units are arranged to ' d' ll f d 'd 'f h 1' 'bl (58) Field of Search ............................... .. 370/330, 331, perm lea y Scan or an 1 enn y I 6 most 6 lgl 6 access
point for association at the highest data rate on the basis of a performance criteria at the current data rate.
453, 440, 432 15 Claims, 6 Drawing Sheets
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