【 Weak current College 】 what networks can play upon the intelligent home appliances

The rapid development of the network, today there are more and more applications extend to family. With easy to install and operate a simple networked intelligent appliances is one of a successful application. As the popularity of broadband networks, network equipment and digital information products were introduced in addition to driving many innovative network application services, but also to accelerate the development of the digital home, further realization of intelligent home dream. In the industry for the definition of a smart family without a specific common, but mostly for how to integrate these different features of network appliance equipment to achieve automation, networking and intelligently target efforts provided to people a more comfortable, convenient and safe home environment. This article is for smart home network technology for in-depth analysis and discussion.

Home networking technology

In General, there are dozens of modern families more than home appliances or equipment. This means that future family will have many different uses of intelligent home appliances and information products, if you want to integrate the diversity of devices that require a common network platform. In the integration of technology, home networking technology plays a crucial role. Home network according to the functional distinction can generally be divided into appliance control network, information network and multimedia audio and video network, three major categories.

Appliance network belongs to low speed control network, mainly TV, refrigerator or washing machine, etc, through the addition or built-in communication module to achieve the purpose of home appliances networking. Such a network patterns, the current global and there is no uniform technical standards, different countries have different technical standards and support for manufacturers. The transmission speed is usually 10kbps following. Currently in the United States Code for SCP/UPnP, LonWorks, Japan specification of Echonet and European norms of KNX. Information networks are used to connect to the computer for data transmission and switching network, the network configuration of the unified communication protocol comparison, the schema is also more familiar, are based on TCP/IP protocol. With high-definition digital TV, plus entertainment digital audio-visual devices with the increasing popularity in the home, the future digital home also exists in tandem with these digital audio-visual devices of broadband multimedia audio and video network.



HomePNA application range

No matter what kind of uses of network technologies, it can be roughly divided into wired and wireless second largest type, as shown in the figure. Wired network technologies including: Ethernet, HomePNA, HomePlug, wireless network technology, IEEE802.11, HomeRF, Bluetooth and Zigbee. In some of these technologies is already a very mature and well known for everyone, and some of the technology is being developed. For a comparison of the well known technologies such as Ethernet, IEEE802.11, etc, because there are a lot of books and technical papers are available for reference, here is no longer narrative. The following selection of only a few applications in the digital home of technology standards.

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HomePNA full name for the purpose of HomePhone-lineNetworkingAlliance developed through existing home phone line networking of a technical specification. Organization's principal members are IBM, HP, AT & & T, Intel, 3COM and Broadcom, etc. HomePNA standard and Ethernet as the OSI 7 layer, physical layer and link layer. In the versions support HomePNA1.1 to 1Mbps transfer speeds, HomePNA2.0 versions may support to 10Mbps, while in the latest HomePNA3.0, can support to 100Mbps speeds, and with services such as ADSL, ISDN-compatible.

HomePNA has the following characteristics: speed, using HomePNA programme access rate Mbps downlink (HomePNA1.0)/10Mbps (HomePNA2.0). This is the dial 56Kbps simply incomparable; charges low, users use the network services do not have to pay additional telephone charges, monthly or hourly flexible charging method, it is cost-effective; free dialing, at any time online, waive the Redial if line is full of trouble, even if you don't understand the network knowledge can also be easily shared on the Internet; the Internet, some families have more than one PC or laptop, use our HomePNA control cards can be shared and within families; construction of simple Internet sharing without rewiring, just the phone line ends with a simple-to-end equipment, does not destroy the decoration, without prejudice to the use of the phone.

HomePNA shortcomings: Although a HomePNA is a new technology, lower cost, but it's the transmission distance is too short, and long distance transport is still a need for other technologies (such as ADSL, Cablemodem, etc.) to help implement, say that this is a big regret. In addition, signal noise is also a problem, because the network environment is one of the family, signal transmission must be subject to other household appliance noise impact. However believe that as technology develops, HomePNA will gradually maturing into the millions.

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In most families, since the number is usually inferior to the telephone line interface power supply cable to the socket-intensive, with previous experience in power line communication of many problems, through the ongoing rapid development of communications technology, has been improved so that the power line communication (Powerlinecommunication; PLC) in recent years in the development and application of the family, more attention than HomePNA.

Power line communication, transmission speed reached more than 1Mbps high-speed communication technology, in the family applications mainlyThe HomePlug power line Coalition (HomePlugPowerlineAlliance) specification of the launch.

HomePlug power line coalition is a non-profit institution, was established to build a power cord for the industry standard for home Internet access. Union by the DS2, Intellon, Motorola, Panasonic and TexasInstrument, about 50 or so of the industry's leading manufacturers of an organization. In June 2001, the HomePlug Alliance in North America for 500 families of tests, based on these test results of the verification, complete HomePlug1.0 standards.

The main emphasis lies family HomePlug information network services, shipping data carrier frequency higher data transmission speeds are faster. HomePlug1.0 bandwidth theoretically up to 14Mbps, (the actual performance of approximately 4 ~ 8Mbps), but for MP3, CD and other media information delivery is sufficient, but for the delivery of information in huge multimedia audio and video information, so that bandwidth will result in delay, the impact of program quality.

In order for the broadband connection across every family, HomePlug1.0 next generation specification is expected to reach HomePlugAV 200Mbps-level network connection speed. From the name it is not difficult to understand how it is for the transmission of video (AudioandVideo; AV) information. HomePlugAV family power cord on the transmission of audio, video streaming for the purpose of enhancing and optimizing network bandwidth, providing audio-visual entertainment services to meet the family computer, Internet and network resource sharing and other applications.

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(SimpleControlProtocol, simple control protocol)

SCP is a Microsoft advocated by a compact control protocol, is intended for household appliances control network design, the use of this agreement to construct a home appliance control network, enable the device and the device can be in high security, stability and strong low-speed network to achieve the purpose of mutual communication. The present Protocol technology only supports power cable communications. As a control needs appliance network, usually does not require a large amount of information passed, but calls for an immediate reaction and reliable transmission. Therefore, the same is with the power cord as a communication medium, SCP and HomePlug's carrier frequency, modulation and network bandwidth are quite different. Current SCP carrier transceiver (transceiver) chip from Israel ITRAN and Japan two manufacturer Renesas. Overall, its carrier Transceiver IC price and performance, quite competitive.

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LonWorks is a decentralized control network technology, it is a United States Echelon Corporation launched in 1990, using LonTalk Protocol, this agreement follows the International Organization for Standardization (ISO) as defined by the Open Systems Interconnection (OSI) model.

LonWorks application early is in industrial control and building automation, in recent years, their application across all areas of automation, home automation is also included. Lonworks technology supports a number of different transport interfaces and the topology. Because LonWorks technology development for ten years, their power line transmission noise resistance chip in with high attenuation power cable channel has a very good performance. Only its price and overall development costs are relatively high, if the application in the low price of household electrical equipment, for their overall price high impact on the user's purchase.

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"Bluetooth" (Bluetooth) is a bit in the 10th century King who unified Denmark, he will then Sweden, Denmark and Finland unifies. Used his name to name this new technology standards, will unify fragmented situation. Therefore, the sponsor of the Bluetooth technology Sweden's Ericsson (Ericsson) company name to express it through to the brand new wireless transmission technology in global marketing and become the global standard of ambition. Bluetooth standard by SIG (special interest group SpecialInterestsGroup) was founded to develop, the Group was founded in May 1998, including Ericsson, Intel, Nokia, Toshiba and IBM and other companies now have more than 1000 companies to join the camp. Including like Motorola, Sanyo, etc. larger communications equipment manufacturers, and even many watches and game manufacturers are starting to join the Bluetooth SIG. It is expected that the future of the digital home is filled with various brands in the equipment of the "Bluetooth" technology of new products.

Bluetooth (Bluetooth) technology is a short-range wireless technology, wireless personal area network (WPAN WirelessPersonalAreaNetwork;) open standard technologies. Provide fixed device or mobile device communications environment to establish a common radio gets interface to enable communication devices in a wireless scenario, in close range to communicate or operation is a low-power wireless technology. The transmission frequency band for the global public 2.4GHzISM band, with 1Mbps transfer speeds and 10 ~ 100 m distance.



Bluetooth technology allows you to close in the cheapest to several sets of digital equipment (various mobile communication equipment, communication equipment, computer and terminal equipment, various digital system <包括数码照相机、数字摄像机等> even all kinds of home appliances, automation devices) Reticular linked. Bluetooth technologyWill be the network interfaces of various peripheral devices, unified bridge banned device connection shackles, and replace it with a wireless connection. Building a home network, Office network and the ideal means of mobile networks. At present, have installed Bluetooth chip for mobile telephone can be wireless, which greatly saves your call costs.

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Zigbee technology is a short-range wireless communications technology belongs to, has a low cost, low power consumption, bi-directional transmission characteristics. The main emphasis lies in the development of an easy-to-build low-cost wireless network. In the early stages of product development to industrial sensor network, provides induction identification, lighting and safety control, etc. Transmission speed between 20kbps ~ 250kbps, as the transmission distance from slowing of growth.

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UWB (UltraWideBand; and the UWB) is a short-range wireless technology, with low costs and low power dual advantage, its bandwidth of up to hundreds of Mbps, suitable for multimedia and entertainment applications. Basically, the transmission speed of up to 100Mbps of ultra wideband chip technology that is able to provide video and audio streaming services, and has the great advantage in entering the consumer electronics market. Standard in IEEE802.15, in addition to the integrated Bluetooth (Bluetooth), technical specifications, but also the development of high-speed transmission of UWB and ZigBee low power consumption, which could in the future to shine in digital home.

From the frequency domain, ultra-wideband is different from traditional narrowband and broadband, it's band. Narrow-band refers to the relative bandwidth (signal bandwidth and center frequency ratio) is less than 1%, relative bandwidth in 1% to 25%, known as broadband, relative bandwidth greater than 25%, and the center frequency greater than 500MHz are known as ultra wideband (table 1).

From time-domain, ultra-wideband systems different from traditional communication systems. General communication system is carried out by sending RF carrier, and UWB signal modulation is used up, the placement of the temporal pulse direct realization of the modulation, ultra-wideband transmission process the modem information placed in a very wide band, and in the process, the length of time, to determine the bandwidth occupies the frequency range. As a result of UWB transmission power limited, thereby limiting the transmission distance as far as data show, UWB signal valid transmission distance of 10 meters, therefore in the civil context, UWB universal positioning in the personal area network category.

Overall, applied to the family of audio and video transmission network technologies to the current development of technology, high speed power line communication technology HomePlugAV and UWB wireless communication technology, are suitable for families and music video information transmission. HomePlugAV has the advantage of using family in both the power line carrier signal, can be saved wiring cost and construction headaches; UWB is a high speed, low power consumption and low-cost wireless communication technology, suitable for applications requiring a high quality service for wireless personal area network, and other fields.

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Full name as UPnP, is a Microsoft extension UniversalPlugandPlay originally in computer hardware Plug and play concept to networking devices for a variety of devices on a network connection can dynamically join a network. Connection of hardware platforms including various digital electronics products, including computers, home appliances and other equipment can become a member of the UPnP network. The overall structure of a distributed, open network architecture. The UPnP framework is based on the agreement, the use of standard Internet protocols, independence can be applied to a variety of different operating systems. Through UPnP network six running processes: addressing (Addressing), Discovery (Discovery), description (Description), control (Control), events (Eventing), rendering (Presentation), thus establishing a complete UPnP network operation mechanism.

Smart family prototype system structures

In describes some common wiring technology, you need to select the appropriate technical architecture, construction of intelligent home system. Below I will to SCP and UPnP technology, simulation of a prototype system of intelligent home.

First of all, you can include networked home appliances device connection SCP communications module that enables these devices to take advantage of the family of the existing power lines as the communication medium, the formation of Internet appliance control network.

Then through SCP-UPnP bridge, household appliances control networks and information networks for connecting, as a result, household electrical equipment can be based on the IP network, to become a member in a UPnP network domain, reach the purpose of the appliance control.

1 the establishment of a network appliance control

Here, we will adopt ITRAN production IT800-SCP power cable communications chip to SCP Protocol appliance control network. A SCP device component model includes the application subsystem and communications subsystem of two major components, these two components communicate via SPI interface, as shown in the figure on the right.

2 application subsystem

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This subsystem is a micro-controller, micro-controller perform access appliances device information.

3 communication subsystem

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Communication subsystem core controller for communication protocol, communication protocol controller will signal transmission to the power cord from the power cord, or receive a signal on.

Since each different appliances, so in the communications subsystem to EEPROM to store a variety of information about home appliances。

4 connect the UPnP network

When a device joins the UPnP network, you must have a unique address for identification.

UPnP device is divided into two kinds: one is a managed device (Controlleddevice), the first control point (ControlPoint). Managed devices like servers that provide services; whereas the control point is the use of the services of the client.

UPnP devices can use multicast manner found information (Discoverymessage) and tell the network to any point of interest. Relative control point will search its interest in the managed device.

When a managed device's UPnP network, control points can do not need to install any driver can quickly find what you looking for a managed device, the control points through managed device description and the description of the service, you can get more information on the managed device and control.

5 bridges

The role of bridges, is to make UPnP and SCP to be able to communicate in a mediation procedure. Through the bridge, you can enable UPnP protocol format and SCP protocol format conversions, the aim of achieving mutual communication. This bridge is SCPDeviceDevelopmentKit provides.

For example, when a device's light bulbs and SCP SCP controller to join the SCP network boot bridge. At this point, the SCP devices are UPnP control point for the discovery of and access to its State.

Throughout the implementation process, you can feel to SCP/UPnP technology to construct a simple prototype for the convenience of intelligent home appliances networking. Also learn about SCP appliance network through the bridge, you can access via the UPnP control point SCP network appliance devices.



Written in the last

As a result of technological progress and the improvement of people's living standard, as well as comfortable and convenient lifestyle needs, home appliance information of intelligent home appliances products has gradually become the main focus of the development of household appliances industry. Smart home appliance products, not only can meet the customer demand to provide a good service, but also increased the traditional electrical appliance industry's competitiveness. On the other hand, manufacturers have begun to move information products provide household electrical appliances, information appliance products. Along with the intelligence and the rise of information appliance, construction of an intelligent digital home is no longer a dream.