P-net, bluetooth, ZigBee, ARCnet og TTP
P-net
P-NET Data Link Layer Create and recognize frame boundaries Node address field Control/Status Info length Info field Error det. 2 - 24 bytes 1 byte 0 - 63 bytes 1 - 2 bytes Frame format Bit 0 1 2 3 4 5 6 7 x 1 1 stop bit Address/data bit (1 = address) 8 data bit 1 start bit
Frame: Node address field Each node has a unique node address (NA = 1-125) Bits 0-6 node address 7 request = 0, response = 1 Node address 0 internal applications 126 broadcasting without acknowledge 127 reserved for test.
Virtuel token parsing
Virtuel token parsing
Bluetooth
ZigBee Hvorfor ikke bluetooth eller WLAN . Fx: 50.000 hjem med 100 wireless control/sensor devices. Case 1: 802.11 Rx power is 667 mW = 3.33 megawatt Case 2: 802.15.1 Rx power is 100 mW = 500 kilowatt Case 3: 802.15.4 Rx power is 30 mW = 150 kilowatt Case 4: 802.15.4 power cycle. 1% (typisk duty cycle) = 150 watt!
ZigBee
ZigBee Star netwærk En enkelt ZigBee coordinator med en eller flere ZigBee End Devices (op til 65,536) Cluster tree netværk. Mesh network med routing.
ZigBee … Application (APL) Layer Application Framework ZigBee Device Object Application (ZDO) Application Object 240 … Object 1 ZDO Public Interfaces Endpoint 240 Endpoint 1 Endpoint 0 APSDE-SAP APSDE-SAP APSDE-SAP Application Support Sublayer (APS) APS Security ASL Security APS Message Reflector APSME-SAP Broker Management Security Management Management ZDO Management Plane Service IEEE 802.15.4 defined ZigBee TM Alliance End manufacturer Layer function interface NLDE-SAP - Provider Network (NWK) Layer NWK Security NWK Message Routing Network NLME-SAP Management Broker Management Management MLDE-SAP MLME-SAP Medium Access Control (MAC) Layer PD-SAP PLME-SAP Physical (PHY) Layer 2.4 GHz Radio
ZigBee 4 frame typer: Beacon Data MAC command Acknowledge
ARCNET Token-bus net Host 1 Host 2 Host n ..... Hastighed : max 10 Mbit/s Antal hosts pr. segment: 255 dvs ID: 1-255
Opstart af token Hvis en maskine ikke er med dvs ingen INVITATION TO TRANSMIT i 420 S. Så råber den ''ALLE SKAL DØ'' RECONFIGURATION BURST .... 111111110 111111110 111111110 765 gange Her efter: Når bus bliver IDLE vent 41S + 73 S * (255-ID) ------------------------------------------------------------------------------------ Hvis stabig IDLE så: Send INVITATION TO TRANSMIT til mig selv samt find næste hoat men mindre ID Ellers: Vent til en sender INVITATION TO TRANSMIT til mig
Find NID NID er ID'en for den host med nærmeste lavere ID. NID = ID Send ITT to NID hvis ingen aktivitet i 37,4 S så hop: ellers stop ca 3 km frem samt tilbage= 15 S + 15 S plus opstartstid ca 6.4 S.
Pakkeformat 11 bit Der sendes byte enheder: xxxx-xxxx 110 Invitation To Transmit: ITT 111111 EOT DID DID End Of Transmission: 04Hex To gange Distination ID
Pakkeformat Free Buffer Enquiries 111111 ENQ DID DID Enquiry: 85Hex To gange Distination ID Acknowledgement Negative Acknowledgement 111111 ACK 111111 NAK 86Hex 15Hex
Pakkeformat DataPakke 111111 SOH SID DID DID ... Source ID Start Of Header: 01Hex To gange Distination ID ... COUNT SC DATA CRC CRC 256-N for short packet 1-508 byte 16 15 2 1 X + X + X + X 512-N for long packet 0 for long packet
Data transmision Sender: ID Modtage: DID ITT til ID send FBE send ACK send DataPacket send ACK ITT til NID
TDMA
TTP MEDL-tabel for note 3 Time Buf add. D L I T ..... 3 1 4 5 6 7 5 6 7 .....
Pakkeformat Normal 1 4 0-128 16 Data CRC Header StartOf Frame Header: 1 Bit I/N-frame og 3bit Mode change. Init 1 4 16 CRC Global time, current MEDL index, Membership vector
Tradmark (Name) Application area Technology Capacity Support Tradmark (Name) Application area Technology Capacity Support Controller Area Network (CAN) automotive industry, cars, forklifters, tractors CSMA/CA 40m: 1 mbps 500m: 125kbps Intel embedded controllers (80517). Keil RT-51. DeviceNet from Allen Bradley Profibus Proces control Higher level token rotation. Lower level master slave. 2 mbps on rs-485 Siemens Simatic EN50170 P-net Virtual higher level token rotation. Lower level master slave. 76.8 kbps on rs-485 P-net from Proces Data EN50170 Attached Ressource Computer Network ARC-net Robot control, Marine automation Token bus. 2-5 mbps on rs-485 Mitsubitsi ATOMOS EN50170 Time Triggered Protocol Car automation, x-by wire TDMA 2 mbps Tttech, Tech Univ. of Vienna. Herman Kopetz LON proces control CSMA/CD ... 300-1.2 mbps EcheLon LonWorks Motorola Highway Adressable Remote Transducer (HART) Transducer communication FSK on 4-20 mA Master Slave 3-4 req. / sec. InterBus Procescontrol Master Slave. Summation Frame Protocol 500 kpbs on rs-485 Bitbus radio broadcast and telecommunication systems building automation Master Slave 300 kbps on rs-485 FireWire Connecting video and audio equiptment in PC-env. Combined Daisy Chain and TDMA 50-400 mbps on tw. pair. (4.5 m.) IEEE 1394 Fiber Distributed Data Interface (FDDI) all purpose LAN space applications Token ring 100 mbps on fiber optics or tw. pair. (100km, max 2 km betw. stations.) IEEE 802.5 Industrial Ethernet
Transmission Error Control Tilføje ekstra bit til pakker således at der bliver en given mindste afstand (Hamming afstand) mellem lovlige pakker. Fx. Even paritet som giver Hamming afstand på 2.
Transmission Error Control Hamming afstand: dmin = 5. Max antal fejl der kan detekteres: dmin - 1. Max antal fejl der kan rettes: (dmin - 1) / 2.
CRC - Cyclic Redundancy Check IEEE 802.3 CRC-32: x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x1+1 Dvs 10000 0100 - 1100 0001- 0001 1101 - 1011 0111 ARCnet: CRC-16 x^16 + x15 + x ^ 2 + 1 Dvs 11000 0000 - 0000 0101 CAN bus: CRC-CCITT X^16+X^12+X^5+1 Dvs 10001 0000 - 0010 0001
CRC - Cyclic Redundancy Check List af de mest brugte CRC polynomier CRC-12: X^12+X^11+X^3+X^2+X+1 CRC-16: X^16+X^15+X^2+1 CRC-CCITT: X^16+X^12+X^5+1 CRC-32: X^32+X^26+X^23+X^22+X^16+X^12+ X^11+X^10+X^8+X^7+X^5+X^4+X^2+X+1 The CRC-12 bruges til 6-bits streams. Både CRC-16 og CCRC-CCITT er for 8 bits streams. CRC-32 giver ekstra sikkerhed da der generes en 32 bit Checksum. CRC-32 bruges i fx. (IEEE-802).
CRC - Cyclic Redundancy Check Polynomie: 10011 Data: 1101011011 110000 10011 :1101011011 10011 00001 00000 00010 00101 01011 Remainder Checksum 1011
CRC - Cyclic Redundancy Check
Real-Time trafik på Ethernet
10 Mbit Ethernet % - delen af pakkerne der kom for sent > 2 msek. Data pr. stream: 1.5 Mbps.
Hub og Switch Switch Bridge Hub Fældes net segment
Collision-free Ethernet vha. Hardware Collision domain: Et logisk område i et computer netværk hvor data pakker kan ”kollidere" med hinanden fx: Ethernet. En Switch opdeler i et antal Collision domain’er. Hvis forbindelsen er full-duplex og det et rent switched net er der ingen Collision domain’er. Løser det alle problemer ?????
Switch’et pakke net Pakker skal stadig vændte på at få en connection. DVS: Switch indeholder køer. IEEE 802.1Q Definere 8 prioitetesniveauer.
En anden vej: Prøv fx at styre hvor meget der bliver sagt samt hvornår der bliver sagt noget.
QoS – Quality of Service Delay Jitter Bandwidth
QoS – Quality of Service Løsning: Kapacitet nok. Fx. Telefonsystemet. Reciver buffer. Øger delay og mininere jitter. Begrænsning af senderes bithastighed. Minder delay, mindre jitter og mindre Bandwidth.
Bucket algoritmen En sender buffer. En cyklisk task der er aktiv hvis der er data i bufferen og sender disse data med en passende lav bidhastighed.
Token Bucket algoritmen En sender buffer der fyldes med token token/sek. Senderen sender sine data vha tokens dvs. Nbit pr token fra bufferen.
RETHER ET token-bus pricip på et collision domain fx Ethernet.
RETHER Node 1 Initiator Node n Node 2 ...... Switch-to-RETHER ACK
Voice over IP Typer : H.323: IP telefoni. Standard 1400 sider. SIP: Simplere end H.323. Standard 250 sider.
H.323
H.323
RTP.
RTP.