Interworking between USN and IP Networks Ki-Hyung Kim Ajou University, Korea

Transcription

1 Interworking between USN and IP Networks Ki-Hyung Kim Ajou University, Korea

2 Standards in USN Interworking Issues Contents 2

3 Standards in USN MAC layer IEEE IEEE b IEEE a IEEE Network layer and above ZigBee IP-USN (6lowpan) TinyOS Various architectures in the literature 3

4 Technical Comparison between ZigBee and 6LoWPAN II Wireless Sensor Network (TinyOS, literature, etc) ZigBee Network 1:1 Comunication Control another node Sink Node ZigBee Gateway Gateway 6LoWPAN Send data periodically Query Data Indirectly control node Directly control node and p2p communication End-to-End connection across network Control another node Query DB Server Data Host Get information from internet Web Server 4

5 Address Issue of IEEE bit PAN ID is the identifier of WPAN Two addresses in IEEE MAC layer EUI 64 bit address given by the manufacturer (optionally, + PAN ID) 16 bit short address assigned by the coordinator dynamically (optionally, + PANID) ZigBee uses the two addresses without PANID (does not consider inter-pan routing) 6lowpan uses two IPv6 addresses 64bit prefix + EUI64bit interface identifier of 15.4MAC 64bit prefix + PAN ID (16bit) + 16bit short of 15.4MAC 5

6 ZigBee

7 What is IEEE and ZigBee Application Layer ZigBee Stack IEEE Stack (MAC) PHY: 868/915MHz PHY: 2.4 GHz MAC: Medium Access control PHY: Physical layer ZigBee defining upper protocol layers: -Application Profiles -Application Framework -Network and Security layer IEEE : standard defining PHY and MAC IEEE a: Alternate PHY IEEE b: revision of PHY and MAC 7

8 ZigBee Alliance ZigBee Alliance Promoters MLME-SAP APSME-SAP ZDO Management Plane ZigBee Public Interface ZigBee Specification v1.0 opened from June 2005 <ZigBee v1.0 Protocol Stack Architecture> 8

9 IEEE vs ZigBee ZigBee: The stack layers creates the network by: Network layer Join and leave networks Route frames Discover routes Discover one-hop neighbours Apply security Starting a network (coordinator) Assigning addresses (coordinator) Application Support Sublayer Tables for binding Forward messages between bound devices 9

10 Network Layer SAP 10

11 ZigBee Device Types ZigBee Coordinator (ZC) One and only one required for each ZB network. Initiates network formation. Acts as PAN coordinator (FFD). May act as router once network is formed. ZigBee Router (ZR) Optional network component. May associate with ZC or with previously associated ZR. Acts as coordinator (FFD). Participates in multihop routing of messages. ZigBee End Device (ZED) Optional network component. Shall not allow association. Shall not participate in routing. 11

12 Tree-Structures Address Assignment 12

13 ZigBee Ad-hoc Network Formation 13

14 Tree-based Hierarchical Routing 14

15 Table-based On-Demand Routing Table routing, in the case where a routing table entry for the destination exists, simply consists of extracting the next-hop address from that entry and routing the message through (or to) that address. 15

16 Routing Cost 16

17 Gateway architecture of ZigBee Bridge between two ZigBee networks Tunneling between two ZigBee networks ZigBee internet ZigBee Gateway between ZigBee and Ethernet, IP, Mobile, WiFi, PLC etc Address translation (NAT) should be applied. 17

18 6LoWPAN (IP-USN)

19 6LoWPAN A new BOF was held during 61 st IETF at D.C. 6lowpan (IPv6 over IEEE ) Invensys, Hellicom, Intel, Sun, Panasonic An official Working Group begun on March 2005 Why IPv6 More suitable for higher density Statelessness mandated No NAT necessary Possibility of adding innovative techniques such as location aware addressing IEEE 64 bit address subsumed into IPv6 address 19

20 Challenges of LoWPAN Impact Analysis Addressing Routing Security Network management Low power (1-2 years lifetime on batteries) Storage limitations, low overhead Periodic sleep aware routing, low overhead Simplicity (CPU usage), low overhead Periodic sleep aware management, low overhead Low cost (<$10/unit) Stateless address generation Small or no routing tables Ease of Use, simple bootstrappin g Space constraints Low bandwidth (<300kbps) Compressed addresses Low routing overhead Low packet overhead Low network overhead High density (<2-4? units/sq ft) Large address space IPv6 Scalable and routable to *a node* Robust Easy to use and scalable IP network interaction Address routable from IP world Seamless IP routing Work end to end from IP network Compatible with SNMP, etc 20

21 Problems and Motivations of 6LoWPAN No method exists to make IP run over IEEE networks Worst case.15.4 PDU 81 octets, IPv6 MTU requirements 1280 octets Stacking IP and above layers as is may not fit within one frame IPv6 40 octets, TCP 20 octets, UDP 8 octets + other layers (security, routing, etc) leaving few bytes for data Not all adhoc routing protocols may be immediately suitable for LoWPAN DSR may not fit within a packet, AODV needs more memory, etc Current service discovery methods bulky for LoWPAN Primarily XML based that needs computing, more memory, etc Limited configuration and management necessary Security for multi hop needs to be considered 21

22 draft-ietf-6lowpan-format-09 Transmission of IPv6 Packets over IEEE WPAN Networks Defines basic packet formats and sub-ip adaptation layer for transmission over 6lowpan Includes framing, adaptation, header compression, address generation, and packet delivery in mesh topology 22

23 Frame Format and Adaptation Layer Single Hop, No Frag HC1 Dispatch HC1 Hdr Multi Hop, No Frag Mesh Dispatch Mesh Hdr HC1 Dispatch HC1 Hdr Single Hop, Frag Frag Dispatch Frag Hdr HC1 Dispatch HC1 Hdr Multi Hop, Frag Mesh Dispatch Mesh Hdr Frag Dispatch Frag Hdr HC1 Dispatch HC1 Hdr Final Destination Field is used for mesh routing Prot_type indicates whether HC(Header Compression) is used or not. 23

24 6LoWPAN Header Details Dispatch Header (extendable) 0 Dispatch Mesh Header IPv6, LOWPAN_HC1, Source Route,??? 0 0x7F Dispatch IPv6, LOWPAN_HC1,??? 1 0 O F Hops Originator Addr, Final Addr 1 0 O F 0xF Hops Originator Addr, Final Addr ( hops) Fragmentation Header dgram_tag dgram_size dgram_tag dgram_size dgram_offset 24

25 Multi Hop, No Fragmentation 2 Bytes 4 Bytes Examples of 6LoWPAN Headers Single Hop, No Fragmentation 1 Byte 0 Dispatch 1 0 O F Hops 0 Dispatch Single Hop, Fragmentation dgram_tag dgram_size 0 Dispatch Multi Hop, Fragmentation 5 Bytes 1 0 O F Hops dgram_tag dgram_size 0 Dispatch Multi Hop > 14 hops 6 Bytes 1 0 O F 0xF Hops dgram_tag dgram_size 0 Dispatch 25

26 확장성 (Extensibility) Deep Networks 1 0 OF Hops Addrs HC1 Dispatch HC1 Hdr 1 0 OF 0xF Hops Addrs HC1 Dispatch HC1 Hdr Mesh Protocols (LOAD, AODV, DYMO, Source route ) Mesh DispatchMesh Hdr HC1 Dispatch HC1 Hdr Mesh DispatchMesh Hdr Proto Dispatch Proto Hdr HC1 Dispatch HC1 Hdr Other Upper Layer Protocols Mesh DispatchMesh Hdr HC1 Dispatch HC1 Hdr Mesh DispatchMesh Hdr HCX Dispatch HCX Hdr Anything Else Mesh DispatchMesh Hdr HC1 Dispatch HC1 Hdr Mesh Dispatch Mesh Hdr XXX Dispatch XXX Hdr YYY Dispatch YYY Hdr ZZZ Dispatch ZZZ Hdr 26

27 Header Compression Most common IPv6 header: IP version = IPv6 IPv6 source and destination both are link local Length inferred from IEEE header Traffic Class and Flow Label both are 0 Next Header = UDP, ICMP or TCP Only need to carry Hop Limit This common case is highly compressible 2 octets instead of 40 Alternate encoding allows further compression to 1 octet (to be done) UDP header compression Allows use of 4 bit (potentially 8 bit) port ranges (P+range) UDP header compressible from 8 octets to 4 TCP header compression can use existing specs with proper prot_type (to be done) 27

28 IP-USN Router Architecture IP-USN Node IP-USN Router Host of IP networks IP-USN Router IP-USN Node Application Layer Transport Layer (TCP/UDP) Network Layer (IP) Ethernet or other MAC/PHY Application Layer Transport Layer (TCP/UDP) Ethernet or other MAC/PHY Network Layer (IP) Adaptation Layer IEEE MAC/PHY Application Layer Transport Layer (TCP/UDP) Network Layer (IP) Adaptation Layer IEEE MAC/PHY 28

29 Problem Statement of Neighbor Discovery IPv6 ND requires frequent signaling messages RA to all node multicasts, NS, DAD, NUD messages IEEE does not have multicast support at the MAC layer LowPan network is essentially low-energy network reducing number of signaling messages are necessary Current IPv6 ND is designed for larger sytems with constant source of power LowPan network could be an adhoc network of low-power devices LowPan assumes routing to happen at the Link-layer 29

30 Goals of ND in 6lowpan Minimizing periodic ND multicast messages Reducing total number of Neighbor Discovery related messages Defining default ND parameters that work for 6LowPan networks All-node multicasts for unsolicited RA Solicited node multicast for DAD All-router multicast for Router solicitation Routing at Link-layer : Is RA necessary to propagate to all nodes at the LowPan network? Who does the prefix advertisement? 30

31 Case Scenario of USN&IP Interworking KT 의기상 / 해양관측센서네트워크

32 기상해양센서네트워크전체구성도 설치지역및구간내역 구좌읍사무소 종달 2.50km 2. 83km 4.16km 5.57km 4.19km 5.30km 4.17km 제주도성산포지역 3.83km 4.66km : IP-USN 설치장소 : Wireless Mesh 설치장소 6.30km 성산포기상관측소 32

33 구성개념도 계획구성도 6lowpan 센서 6lowpan G/W IPv6 DualStack Router New AWS 6lowpan 센서 6lowpan G/W IP Cam-CCTV (Option/Planning) Wireless Mesh Network IEEE802.11g/2.4GHz/OFDM WEP/AES Encryption IPv6 DualStack Router Large Display PC1 PC2 PC3 6lowpan 센서 6lowpan G/W IPv6 DualStack Router New AWS KOREN IPSEC VPN concentrator 33

34 Mesh 구성 메쉬네트워크진행상황 34

35 종달초소 WMN 설치위치별상세내역 1 35

36 WMN 설치위치별상세내역 2 국립해양조사원조위관측소 36

37 성산포기상관측소 - 센서노드 9 개설치 기상센서네트워크설치 37

38 기상센서네트워크설치현황 - 성산포기상관측소 (1) IP-USN 센서노드 38

39 기상센서네트워크설치현황 - 성산포기상관측소 (2) IP-USN 설치현황 39

40 기상센서네트워크설치현황 - 성산포기상관측소 (3) IP-USN Router 6LoWPAN을 IPv6 네트워크와연결 IPv4/6 터널링및방화벽기능 SNMP 프록시에이전트기능 Pxa255 arm MCU 64Mbyte RAM 64Mbyte ROM 40

41 기상센서네트워크노드개발 IP-USN sensor node ATM 128L 8bit Microcontroller 128k Bytes flash memory 4k Bytes SRAM 8MHz Speed Extension Memory 32k Bytes CC2420 GPS 시간동기화, 위치정보 RS232c 기상정보수집 41

42 프로토콜스텍, 데이타처리태스크구현 6LoWPAN Stack IPv6 stack Adaptation LOAD HiLOW Neighbor Discovery IEEE 의 16bit, 64bit 주소를이용한 IPv6 주소자동생성 TCP / UDP 패킷을이용한데이터전송 Socket-like API 제공 42

43 IP-USN 기반제주기상해양센서네트워크 U-infra Conference 전시 RFID/USN 컨퍼런스전시 43

44 기상센서네트워크설치현황 - 성산포기상관측소 (4) 기상해양센서네트워크관제실 44

45 기상정보수집서버 (1) 35 개의센서노드로부터기상정보수집화면 45

46 기상정보수집서버 (2) 성산포기상관측대에설치된센서노드로부터수집된정보들 46

47 기상센서네트워크매니져 47

48 해양센서네트워크 ( 해양조 사연구원 )

49 Satellite 해양 2000 호 IP-USN 구축 해양 2000 호선상에센서네트워크구축 - 목적 : 풍향. 풍속측정 위성 원격지모니터링 해양 2000 호 ( 센서네트워크구축 ) 49

50 해양 2000 호 IP-USN 시험 (1) 50

51 51

52 설치결과 52

53 해양 2000 호 IP-USN 시험 (2) 설치내역 - 선수의타워상단설치 - 풍향, 풍속센서 1조설치 - 예상토폴로지 - 풍향, 풍속센서 > 중계노드 > 게이트웨이 - 풍향, 풍속센서 > 게이트웨이 53

54 Technical Issues in USN&IP Interworking

55 Technical Issues in USN&IP Interworking Definition of socket functions socket &ioctl Interworking with TCP and UDP Interworking with ICMP (ping and traceroute) Interworking with upnp Interworking with http, xml Interworking with IPSec Interworking with Multiple Gateways Interworking with SNMP Service discovery in USN 55

56 Interworking with Internet 56

57 Simple Service Location Protocol(SSLP) When 6lowpan nodes come in close proximity, they need to locate one another and services in proximity Related Works SLPv2 in Internet SSDP(Simple Service Discovery Protocol) of UPnP Jini These are not suitable for 6lowpan Limited packet size Limited processing power Dynamic nature of network topology SSLP Provides mechanisms for locating services and peer nodes in proximity Interoperates with SLPv2 on Internet 57

58 Service discovery in SSLP SSLP(Simple Service Location Protocol) 기존 IETF 표준인 SLP 와유사하게동작함 User Agent, Service Agent, Directory Agent (SLP) + Translation Agent (SSLP) TA(Translation Agent) 에의해서 SLPv2 와호환성유지 58

59 Service discovery in SSLP II 2-1 Nearest SA replies to the SrvRequest 1-1 Estimate the location of UA 2. 6lowpan SA replies to the SrvRequest 1 Service Request 59

60 SSLP General Header SSLP Header Format Message Type Abbreviation Msg-ID Service Request SREQ 1 Service Reply SREP 2 Service Registration SREG 3 Service Deregistration SDER 4 Service Acknowledge SACK 5 DA Advertisement DADV 6 SA Advertisement SADV 7 60

61 Conclusion USN connectivity with IP Address Translation (NAT 방식 ) IP-USN Technical Issues in IP interworking 61