- - 43-8011 3-5-1 E-mail: watanabe@inf.shizuoka.ac.jp [Invited Paper] Wireless Networking: the urrent Status and the Future - oward Ultimate Usage of ime/space/frequency Spectrum- akashi WAANAE Graduate school of science and technology, Shizuoka University 3-5-1 Jouhoku, Naka-ku, Hamamatsu-shi, Shizuoka, 43-8011 Japan E-mail: watanabe@inf.shizuoka.ac.jp Abstract In recent years, wireless networks including ad hoc networks, sensor networks and mesh networks which do not require any fixed infrastructure as well as wireless LAN have been attracted a great deal of attention. hey will be important and fundamental technologies to achieve ubiquitous society. his paper mainly presents the current status of communication protocols for wireless networks and their application, especially medium access control (MA) protocols of ad hoc networks using smart antennas to enhance spatial reuse. It also provides a view of the future wireless networks toward ultimate usage of time, space and frequency spectrum. Keyword Ubiquitous Network, Ad Hoc Network, Smart antennas, ime/space/frequency resource, Ultimate usage of resources - 5 - his article is a technical report without peer review, and its polished and/or extended version may be published elsewhere. opyright 011 by IEIE
1 SN (signal noise ratio) MIMO MA SMA/A based IEEE 80.11 edium Access ontrol Hidden terminal Problem S/S exchange to reserve channel before data communication MAA, MAAW, IEEE 80.11 ecent development Power control ate control Antenna directivity Multi-channel usage Security... Power control irectivity control ate control hannel contorl 011056 S/IN 1 011056 S/IN Wireless networking with smart antennas Issues on directional protocols Smart antenna control antenna directivity electronically Adaptive array Switched beam antenna Sector antenna A ESPAElectronically Steerable Passive Array adiator VivatoUSMotiaUS Spatial reuse and extending transmission range Location info eafness irectional HP irectional EP SWAMP I-MA, MA/A, Alternative ast S, orthogonal routing ooperation with neighbors Protocols considering real radio propagation Antenna minor lobes SWAMP-, MA-P roadcasting, N Multi-lobe multi-rate transmission Fading ifference between carrier sense & data receive area Improve spatial Extend Omni-directional reuse transmission antenna 011056 S/IN range 3 011056 S/IN 4 (1)SWAMP Smart antennas based Wider-range Access MA Protocol O-mode O O (Omni-directional transmission range ommunication mode) Omni-NAV Acquisition of NHI () A S(O) SOF(O) S(O) S(O) S(O) SOF(O) AA(L) AK(L) L L d A s NHI able I X NHI Lx Omni-NAV Acquisition of NHI () NHINext Hop irection Information SOF: Start of Frame 011056 S/IN E-mode (Extended transmission range ommunication mode) L 30 L 70 A M S (H) S (M) AA (M) AK (M) H d Aggregate hroughput (Mbps) hroughput performance 8 7 6 5 4 3 1 0 SWAMP (O+E) SWAMP (O) IEEE 80.11 0 5 10 15 0 5 30 35 40 λ (packets/s) 5 011056 S/IN ~3.5 times higher 6-6 -
9 14 19 4 () MA for Hidden erminals irectional HP Occurs when the gains of directional and omni-directional antennas are different [houdhury et al. Mobiom 0] Gain (directional) Gain (omni-directional) Pr PtGtGr S AA A Hidden terminal Approach for directional HP MA Notify the on-going communication to potential HP High Gain S ackward S Propose three MA protocols elayed S outing Orthogonal routing 011056 S/IN 7 011056 S/IN 8 MA protocols for directional HP (1) ackward S (S) ransmitter sends S toward 180 deg. back before data transmissions Potential H sets NAV Issues Overhead of adding S frame Postpone other communications even if the transmitter fails the data transmission MA protocol Evaluation (1) Evaluation of HS, S (1) straight model irectional H X NAV ackward S S S 011056 S/IN Performance of HS, S improves Suppress the transmission of Hs 9 011056 S/IN 10 (3) MA A SIN SIN SIN (d) (Mbps) 4.56 54 4.05 48 18.80 36 17.04 4 10.79 18 9.03 1 7.78 9 6.0 6 011056 S/IN 11 MA 1 M1N010 36 865 M1N111 88 (GPS) SINAA 011056 S/IN 1-7 -
500[m ] 80.11g 104byte 300sec 15dm -80dm 3. keyholem1n1(11) 10 di 30-50 di 0-0di 0 70 10 90 3 36 88(336) 500[m] 0 5() 1) Keyhole ) ESPA 011056 S/IN 13 keyholem1n1 (010) 011056 S/IN 14 15% UNAGI/ESPA (4) Ubiquitous Network testbed with Adaptively Gaincontrolled antenna for performance Improvement IEEE 80.15.4, MA in MA GPS, Gyro(P/IP) MA ESPA antenna keyhole()keyhole() 15% ESPA()ESPA note P F module micro controller 011056 S/IN 011056 S/IN 15 writer 16 One of Experimental esults Experiment by USP/GNU adio 1 3 4 X hroughput improvement X (m) P for operating GNU adio USP Antenna controller Array-type patch antenna Experimental radio site 5.11GHz 4 transmitters Shizuoka Univ. ommunications esearch Gp. (SUOM) Wiki for use of USP Prof. Saruwatari at Morikawa Lab (U. of okyo) http://www.mlab.t.utokyo.ac.jp/~saru/usrp (in Japanese) 011056 S/IN 17 011056 S/IN 18-8 -
ISM, F, No.6, Q, 009.6 () cf. A 5 5.11GHz 7 http://www.soumu.go.jp/soutsu/tokai/musen/tokutei/menkyo.html 011056 S/IN 19 011056 S/IN 0 UNAGI 011056 S/IN 1 0170070 : 0071000 Wireless World esearch Forum (WWF) 010 4 011056 S/IN isco Systems 010 Step1 011056 S/IN Step 3 Space E F G Frequency A 011056 S/IN ime 4-9 -
100m 1m 1mm 1μm Friis P 1 1 4 d oenlarge P, increase G, G, increase P, or increase, decrease d G G P : received power : wave length d : distance between x and x G G : antenna gain of x : antenna gain of x P : x power : and width Sr :Signal strength Nr : Noisestrengh P log (1 Sr / Nr) ( bit / sec) 011056 S/IN 5 011056 S/IN 6 10 5 100 MHzPHz 011056 S/IN 7 011056 S/IN / / 8 3 011056 S/IN 9-30 -