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Smart Home Technologies: 

Smart Home Technologies Networking

Networking for Smart Homes: 

Networking for Smart Homes Requirements Network Topologies Technologies Networking Service Discovery

Requirements: 

Requirements Noise Rejection Network has to allow for reliable communication Requires preservation of data and synchronization of data lines Bandwidth Smart Homes can contain many sensors and actuators Sensor data can be generated at different rates Connectivity Sensors have to be connected to processing units Integration Network structures have to be integrated into buildings Privacy and Security Smart Home networks will transfer private and sensitive data

Bandwidth Requirements Example: 

Bandwidth Requirements Example Camera (15) – 320x240, 8-bit color Motion (15) – distance, direction, velocity Temperature (12) Humidity (12) Light (12) – frequency, intensity Microphone (12) – 8000 Hz Gas (4) Pressure (100)

Bandwidth Requirements: 

Bandwidth Requirements

Other Bandwidth Requirements: 

Other Bandwidth Requirements Audio Phones (16 kHz, 8 bit) Radios (44 kHz, 16 bit) TVs (44 kHz, 16 bit) Media players (44 kHz, 16 bit) Monitoring (16 kHz, 8 bit) 2.4 Mbits/sec (one each) Internet, control, … Video Phones (30fps, 320x240, 8-bit color) TVs (60 fps, 1024x768, 24-bit color) Video players (60 fps, 1024x768, 24-bit color) Monitoring (30 fps, 320x240, 8-bit color) ~6.9 Gbits/sec (one each)

Other Bandwidth Requirements: 

Other Bandwidth Requirements

Other Network Requirements: 

Other Network Requirements Worst-case throughput: 10 Gbits/sec Maximum throughput: 5 Gbits/sec Quality of Service (QoS) Audio, video Plug and play (service discovery)

Network Topologies: 

Network Topologies Infrastructure-Based Networks Pre-defined routes through the network Nodes can directly address each other and routers forward packets appropriately Addition of nodes changes the routing pattern Point-To-Point Networks Every node has a connection to every other node Communication is directly between the nodes High overhead setting up the connections for new nodes Ad-Hoc Networks Routes are determined “on the fly” and can change Nodes forward signals for other nodes Addition of nodes can be handled relatively straightforwardly

Topologies (Point-to-Point): 

Topologies (Point-to-Point) Every device is connected to every other device Good points simplest approach no addressing needed everyone is your neighbor you can always talk to your neighbor Bad points number of ports/lines grow relatively quickly with the number of devices A B C D

Topologies (Hierarchy): 

Topologies (Hierarchy) Devices are connected via hubs to other devices If everyone is connected to a single hub, it is called a Star topology Good points fewer connections devices can have neighborhoods Bad points you need an address you may have to wait to talk to a neighbor asymmetric communication with some devices A B C D

Topologies (Broadcast): 

Topologies (Broadcast) All of the devices are connected to a single wire Good points single wire everyone is your neighbor Bad points you need an address you may have to wait to talk to anyone collisions can occur communication times become statistical A B C D

Physical Addresses: 

Physical Addresses If more than two devices are on the same wire (bus), you will need an address to send and receive data Approaches separate vs. combined data/address lines hardwired vs. selectable address Issues as the number of devices increase, the address space (size of the address) must increase hardwired addresses may tell you nothing about the network topology addresses will be used up by devices that might not be on-line so your address space may be too big, causing too much overhead A B C D 0001 1111 1000 1100

Virtual Addresses: 

Virtual Addresses A solution to some physical address problems is a virtual address the address space (size of the address) can be reduced by only giving addresses to on-line devices addresses can be set up to support network topology Approaches fixed vs. run-time addresses universal vs. p-to-p addresses Issues how to assign them their relationship to the physical address A B C D 00 01 10 11

Network Technologies: 

Network Technologies Wired Phone Line Power Line New Wire Wireless RF Infrared

Wired Network Technology Examples: 

Wired Network Technology Examples Phone line Home Phoneline Networking Alliance (HomePNA) Power line X10 Consumer Electronics Bus (CEBus) HomePlug LonWorks New wire Ethernet (coax, twisted pair, optical fiber) Universal Serial Bus (USB) IEEE 1394 Firewire Home Audio Video Interoperability (HAVi) Specialty: audio, video

Phoneline Networking: 

Phoneline Networking Home Phoneline Networking Alliance (HomePNA) www.homepna.org IEEE 802.3 (Ethernet) Carrier Sense Multiple Access with Collision Detect (CSMA/CD) 10 Mbps (HPNA 2.0) Length: 500 feet

HomePNA Packet: 

HomePNA Packet

HomePNA Frequencies: 

HomePNA Frequencies Standard voice (POTS): 20Hz - 3.4kHz UADSL: 25kHz - 1.1MHz Home network: 5.5MHz - 9.5MHz

Phoneline Network Issues: 

Phoneline Network Issues Random wiring topologies & signal attenuation Home phoneline wiring system is a random “tree” topology Simply plugging in the phone or disconnecting the fax changes the tree This topology can cause signal attenuation Signal noise Appliances, heaters, air conditioners, consumer appliances & telephones can introduce signal noise onto the phone wires

Powerline Networking: 

Powerline Networking Ubiquity of power lines 10+ Mbps Technologies X10 Consumer Electronics Bus (CEBus) HomePlug LonWorks

X10: 

X10 X10 controllers send signals over existing AC wiring to receiver modules X10 technology transmits binary data using the Amplitude Modulation (AM) technique www.x10.com

X10: 

X10 To differentiate the data symbols, the carrier uses the zero-voltage crossing point of the 60Hz AC sine wave on the cycle’s positive or negative transition Synchronized receivers accept the carrier at each zero-crossing point X10 uses two zero crossings to transmit a binary digit so as to reduce errors

X10: 

X10 Every bit requires a full 60 Hertz cycle and thus the X10 transmission rate is limited to only 60 bps Usually a complete X10 command consists of two packets with a 3 cycle gap between each packet Each packet contains two identical messages of 11 bits (or 11 cycles) each A complete X-10 command consumes 47 cycles that yields a transmission time of about 0.8s

Consumer Electronics Bus (CEBus): 

Consumer Electronics Bus (CEBus) Open standard providing separate physical layer specification for communication on power lines and other media Electronic Industries Association (EIA-600) www.cebus.org Data packets are transmitted by the transceiver at about 10 Kbps Carrier Sense Multiple Access/Collision Detect (CSMA/CD) Employing spread spectrum technology (100Hz-400 Hz)

OSI and CEBus (EIA-600): 

OSI and CEBus (EIA-600)

Spread Spectrum Modulation: 

Spread Spectrum Modulation Frequency spectrum of a data-signal is spread using a code uncorrelated with that signal Sacrifices bandwidth to gain signal-to-noise performance

HomePlug: 

HomePlug HomePlug Powerline Alliance www.homeplug.org Spread-spectrum technology

HomePlug: 

HomePlug Speed Support file transfers at 10BaseT-like rates Either node-to-node file transfer or scenarios with multiple nodes performing simultaneous file transfers HomePlug 1.0 (14 Mbps) Voice over IP (VoIP) Maintain adequate QoS while supporting multiple, simultaneous VoIP calls while other nodes are transferring files and during multiple media streams

HomePlug: 

HomePlug Interoperability Interoperate with other networking technologies Co-exist with existing powerline networking technologies such as X-10, CEBus and LonWorks Security Contain strong privacy features Support multiple logical networks on a single physical medium Be applicable to markets in North America, Europe and Asia

LonWorks: 

LonWorks Local Operation Networks (LonWorks) Developed by Echelon Corporation www.echelon.com Provides a peer-to-peer communication protocol, implementing Carrier Sense Multiple Access (CSMA) techniques 1.25 Mbps Works for other wired and wireless media

LonWorks: 

LonWorks A common message-based communications protocol LonTalk protocol implements all seven layers of the OSI model using a mixture of hardware and firmware on a silicon chip Protocol can be run as fast as 20 MHz

Powerline Network Issues: 

Powerline Network Issues Noise Switching power supplies Wound motors Vacuum cleaners, kitchen appliances, drills Dimmers Security Signal attenuation

New Wire Networking: 

New Wire Networking Ethernet (coax, twisted pair, optical fiber) Universal Serial Bus (USB) IEEE 1394 Firewire Home Audio Video Interoperability (HAVi) Specialty: audio, video

Ethernet: 

Ethernet IEEE 802.3 CSMA/CD Up to 1 Gbps IEEE 802.3ae 10GBase-X, 10 Gps Lengths up to 40 km www.ethermanage.com/ethernet

IEEE 802.3: 

IEEE 802.3

Universal Serial Bus (USB): 

Universal Serial Bus (USB) www.usb.org 480 Mbps Plug and Play Hot pluggable Up to 127 devices simultaneously Powered bus 5m maximum cable length

IEEE 1394 Firewire (i.LINK): 

IEEE 1394 Firewire (i.LINK) Digital interface No need to convert digital data into analog and tolerate a loss of data integrity Transferring data @ 100, 200, 400 Mbps Physically small The thin serial cable can replace larger and more expensive interfaces

IEEE 1394 Firewire: 

IEEE 1394 Firewire No need for terminators or device IDs Hot pluggable Users can add or remove 1394 devices with the bus active Scaleable architecture May mix 100, 200, and 400 Mbps devices on a bus

IEEE 1394 Firewire: 

IEEE 1394 Firewire It can connect up to 63 devices @ transfer rate of 400Mbps Up to 16 nodes can be daisy- chained through the connectors Standard cables up to 4.5 m in length for a total standard cable length of 72 m

IEEE 1394 Firewire: 

IEEE 1394 Firewire Flexible topology Support of daisy chaining and branching for true peer-to-peer communication Non-proprietary

IEEE 1394b: 

IEEE 1394b 1394b is a significant enhancement to the basic 1394 specification that enables: Speed increases to 3.2 Gbps Distances of 100 meters on UTP-5, plastic optical fiber and glass optical fiber Significantly reduces latency times by using arbitration Fully backwards compatible with the current 1394 and 1394a specifications

I2C (Inter-Integrated Circuit): 

I2C (Inter-Integrated Circuit) One of the oldest controller buses Philips (1980s) Low-cost chip-to-chip communication link uses two wires to form a clocked serial bus one called Clock (SCL) and the other Data (SDA) the SDA carries address, selection, control, and data Overview multi-master bus (up to 1024 devices) can run at speed up to 3.4 Mbps can be used as a SAN but normal ranges are on the order of 14 cm

Home Audio Video Interoperability (HAVi): 

Home Audio Video Interoperability (HAVi) HAVi is a digital Audio Video networking initiative that provides a home networking software specification Seamless interoperability among home entertainment products Designed to meet the particular demands of digital audio and video www.havi.org

HAVi: 

HAVi Defines operating-system-neutral middleware that manages: Multi-directional AV streams Event schedule Registries Takes advantage of chips built into modern audio and video appliances Provides the management function of a dedicated audio-video networking system IEEE 1394 (i. LINK or FireWire) has been chosen as the interconnection medium

Specialty Wiring: 

Specialty Wiring Audio Coax RCA Speaker wire Video Coax RCA VGA ~100m maximum cable lengths

Automotive Inspired Busses: 

Automotive Inspired Busses

LIN (Local Interconnect Network): 

LIN (Local Interconnect Network) Designed for European cars (still used) Very simple single wire single mastered bus Overview 1 master, up to 16 Slaves uses a message-based protocol maximum distance of 40 m Two data rates 9,600 and 19.2 Kbps

CAN (Controller Area Network ): 

CAN (Controller Area Network ) CAN was designed to support emission control system in European cars but became a general automation control bus Capable of high-speed (1 Mbits/s) data transmission over short distances (40 m) low-speed (5 kbits/s) transmissions at lengths of up to 10,000 m Overview a multi-master bus highly fault tolerant Built-in support for error detection and handling

MOST (Media Oriented System Transport): 

MOST (Media Oriented System Transport) An inexpensive automotive and appliance network 25 Mbps fiber-optic bus for real-time data transfer used in surround-sound systems and CD and DVD players

FlexRay: 

FlexRay Designed to replace LIN, CAN and MOST as a ‘by wire’ solution for future cars It is a fiber-optic bus (like MOST) Current speed 10 Mbps But it is designed to go much higher could run faster than 100 Mbps But remember that is faster than most current micro-controller’s internal bus speed

Wireless Network Technologies: 

Wireless Network Technologies Digital Enhanced Cordless Telecommunications (DECT) HomeRF Bluetooth IEEE 802.11 HiperLAN2 Infrared

General Wireless: 

General Wireless Narrow band Spread spectrum Direct Sequence (DSSS) Frequency Hopping (FHSS) Orthogonal Frequency Division Multiplexing (OFDM)

DECT: 

DECT Digital Enhanced Cordless Telecommunications (DECT) www.dectweb.com Digital radio technology Dynamic channel selection Encryption, authentication, identification 500 Kbps – 2 Mbps Cordless phones

HomeRF: 

HomeRF www.homerf.org Shared Wireless Access Protocol (SWAP) IEEE 802.11 for data DECT for voice

HomeRF: 

HomeRF Specifications 2.4 GHz band FHSS 1.6 Mbps (10 Mbps with SWAP 2.0) 50m range 127 nodes

Bluetooth: 

Bluetooth www.bluetooth.com Ericsson, the principal inventor, borrowed the name from Harald Bluetooth (son of Gorm) The King of Denmark circa 900AD United Denmark and Norway

Bluetooth: 

Bluetooth Specifications 2.4 GHz FHSS (79 channels) 1600 hops per second Error correction 1 Mbps capacity, 780 Kbps throughput 10m distance Low power (1 mW)

Bluetooth: 

Bluetooth Personal Area Networks (PANs) Piconet Collection of up to 8 devices using same hopping sequence Scatternet Collection of piconets, each with different hopping sequence

IEEE 802.11: 

IEEE 802.11 * Data rate degrades with distance.

HiperLAN2: 

HiperLAN2 www.hiperlan2.com 5 GHz 54 Mbps OFDM Automatic frequency allocation TDMA/TDD (Time Division) QoS support

Infrared: 

Infrared www.irda.org Directed – line of sight 1m range Diffuse – reflective Limited to room size Speed 4 Mbps available 16 Mbps coming 50 Mbps possible

Wireless Networking: 

Wireless Networking

Wireless Issues: 

Wireless Issues Distance 2.4 GHz interference Microwave ovens Cordless phones Security Not a backbone solution

Wireless Personal Area Networks (WPAN): 

Wireless Personal Area Networks (WPAN) 802.15.X Intended for low cost, low distance, low power personal networks Often intended for mesh networking E.g. ZigBee (build on 802.11.4)

Ad-Hoc Mesh Networks: 

Ad-Hoc Mesh Networks Ad-Hoc networks of wireless sensors and devices Benefits: Easy to build (require no infrastructure to be available) Dynamic and mobile Fault tolerant (usually no single point of failure) Challenges: Choice of routing to optimize performance QoS Power consumption Synchronization and collision avoidance

Service Discovery: 

Service Discovery Self-configuring devices Device becomes aware of network, network services and other devices Automatic, as opposed to manual (e.g., DHCP, DNS, LDAP) Several incompatible protocols

Service Discovery Protocols: 

Service Discovery Protocols Salutation Service Location Protocol (SLP) Jini Universal Plug and Play Zero-Configuration Networking

Salutation: 

Salutation www.salutation.org Architecture for looking up, discovering and accessing services and information

Salutation: 

Salutation Abstractions for devices, applications, and services Current definitions Printers Fax machines Document storage devices Address book Schedule Voice message answer, send, storage More coming (e.g., display, OS)

Salutation: 

Salutation Capabilities exchange protocol Service request protocol “Personalities” (standardized protocols for common services) APIs for information access and session management

Service Location Protocol (SLP): 

Service Location Protocol (SLP) Developed by Internet Engineering Task Force (IETF) Applies existing Internet standards to service discovery problem www.srvloc.org www.openslp.org

SLP Agents: 

SLP Agents User Agent (UA) The SLP User Agent is a software entity that is looking for the location of one or more services. Service Agent (SA) The SLP Service Agent is a software entity that provides the location of one or more services. Directory Agent(DA) The SLP Directory Agent is a software entity that acts as a centralized repository for service location information.

SLP Messages: 

SLP Messages Service Request (SrvRqst) Message sent by UAs to SAs and DAs to request the location of a service. Service Reply (SrvRply) Message sent by SAs and DAs in reply to a SrvRqst.  The SrvRply contains the URL of the requested service.

SLP Messages (cont.): 

SLP Messages (cont.) Service Registration (SrvReg) Message sent by SAs to DAs containing information about a service that is available. Service Deregister (SrvDeReg) Message sent by SAs to inform DAs that a service is no longer available. Service Acknowledge (SrvAck) A generic acknowledgment that is sent by DAs to SAs as a reply to SrvReg and SrcDeReg messages.

SLP Messages (cont.): 

SLP Messages (cont.) Attribute Request (AttrRqst) Message sent by UAs to request the attributes of a service. Attribute Reply (AttrRply) Message sent by SAs and DAs in reply to a AttrRqst.  The AttrRply contains the list of attributes that were requested.

SLP Messages (cont.): 

SLP Messages (cont.) Service Type Request (SrvTypeRqst) Message sent by UAs to SAs and DAs requesting the types of services that are available. Service Type Reply (SrvTypeRply) Message by SAs and DAs in reply to a SrvTypeRqst.  The SrvTypeRply contains a list of requested service types.

SLP Messages (cont.): 

SLP Messages (cont.) DA Advertisement (DAAdvert) Message sent by DAs to let SAs and UAs know where they are. SA Advertisement (SAAdvert) Message sent by SAs to let UAs know where they are. Unicast or multicast messaging

SLP Template Example: 

SLP Template Example template-type=Net-Transducer template-version=0.0 template-description= This is an abstract service type. The purpose of the Net- Transducer service type is to organize into a single category all network enabled Transducers which have certain properties. template-url-syntax= url-path= ; Depends on the concrete service type. ; See these templates. sample-units= string L # The units of sample that the Transducer provides, for instance # C (degrees Celsius), V (Volts), kg (Kilograms), etc. sample-resolution= string L # The resolution of the Transducer. For instance, 10^-3 means # that the Transducer has resolution to 0.001 unit. sample-rate= integer L # The speed at which samples are obtained per second. For # instance 1000 means that one sample is obtained every millisecond.

SLP Template Example: 

SLP Template Example template-type=service:Net-Transducer:Thermometer template-version=0.0 template-description= The Thermometer is a Net-Transducer capable of reading temperature. The data is read by opening a TCP connection to one of the ports in the service URL and reading an ASCII string until an NULL character is encountered. The client may continue reading data at no faster than the sample-rate, or close the connection. template-url-syntax= url-path = "ports=" ports-list port-list = port / port "," ports port = 1*DIGIT ; See the Service URL <port> production rule. ; These are the ports connections can be made on. location-description=string # The location where the Thermometer is located. operator=string O # The operator to contact to have the Thermometer serviced.

Jini: 

Jini Service discovery for networks of Java-enabled devices www.sun.com/jini www.jini.org

Jini: 

Jini

Jini: 

Jini Services Lookup Communications Java-RMI, CORBA, … Security Leasing Events

Universal Plug and Play: 

Universal Plug and Play Microsoft’s service discovery approach IP-based discovery protocols XML www.upnp.org Examples

Universal Plug and Play: 

Universal Plug and Play Devices Containers for services XML description Services Actions (i.e., methods) Control server Event server State (i.e., variables) XML description

Universal Plug and Play: 

Universal Plug and Play Control points Retrieve the device description and get a list of associated services. Retrieve service descriptions for interesting services. Invoke actions to control the service. Subscribe to the service’s event source. Anytime the state of the service changes, the event server will send an event to the control point.

UPnP Interoperability: 

UPnP Interoperability

UPnP Protocols: 

UPnP Protocols Protocols UDP, TCP/IP, HTTP, XML Simple Service Discovery Protocol (SSDP) Generic Event Notification Architecture (GENA) Send/receive event notifications using HTTP over TCP/IP and multicast UDP Simple Object Access Protocol (SOAP) XML and HTTP for remote procedure calls

UPnP Protocol Stack: 

UPnP Protocol Stack

Zero-Configuration Networking: 

Zero-Configuration Networking Zeroconf (www.zeroconf.org) IETF standard Objectives Allocate addresses without a DHCP server Translate between names and IP addresses without a DNS server Find services, like printers, without a directory server Allocate IP Multicast addresses without a MADCAP server Multicast Address Dynamic Client Allocation Protocol

Zeroconf Protocols: 

Zeroconf Protocols Address autoconfiguration Configure interfaces with unique addresses Determine which subnet mask to use Detect duplicate address assignment Cope with collisions Name-to-address translation Multicast DNS Decentralized

Zeroconf Protocols: 

Zeroconf Protocols Service discovery Service Location Protocol (SLP) DNS Service Resource Record Use expanded DNS for service requests Multicast address allocation Zeroconf Multicast Address Allocation Protocol (ZMAAP) Allocate unique addresses and maintain them over time Prevent reallocation of assigned addresses Be notified of multicast allocation collision

Intelligent Environments: 

Intelligent Environments Network Architecture

Network Architecture: 

Network Architecture Networking Phoneline, powerline New wire Wireless Service discovery SLP, Jini, UPnP, Salutation, zeroconf Communication CORBA, Java-RMI, DCOM

Network Architecture: 

Network Architecture