1、Wireless Technology2GE SecurityTrainingAdventRF Basics/射频技术基础Wireless Technology3GE SecurityTrainingAdventWireless In Everyday Life日常生活中的无线技术Radios/无线电TVs/电视Cordless Telephones/无绳电话Garage Door Openers/车库门开闭器Cellular phones/蜂窝电话4GE SecurityTrainingAdventWireless Technology无线技术RF-the specific cycles p
2、er second of electromagnetic waves traveling through the air without wires.RF is measured in Hertz/RF的测量单位是赫兹Frequency Bands are allocated and controlled by the FCC/美国的无线频率管理机构是FCCCommon uses of RF/常见的RF应用 Cell Phones-900 MHz band/移动电话 Pagers-900 MHz band/寻呼机 Garage Door Openers-300 MHz band/车库门开闭器
3、Security Systems-300-900 MHz bands/安防系统5GE SecurityTrainingAdventFrequency Band Designations/频段划分 Frequency Band Designation Frequency Range Min Max ELF 极低频-Extremely Low Frequency30 Hz 300Hz VF 声频-Voice Frequencies300 Hz 3000 Hz VLF 超低频 Very Low Frequency 3 KHz 30 KHz LF 低频-Low Frequency30 KHz 300
4、KHz MF 中频 Medium Frequency 300 KHz 3000 KHz HF 高频-High Frequency3 MHz 30 MHz VHF 甚高频-Very High Frequency 30 MHz 300 MHz UHF 超高频-Ultra High Frequency 300 MHz 3000 MHz SHF 特高频-Super High Frequency 3 GHz 30 GHz EHF 极高频 Extremely High Frequency30 GHz 300 GHz 6GE SecurityTrainingAdventWireless Security S
5、ystems无线安防系统40 MHz-24 Wavelength,great open air range,poor structural penetration,good battery life./24英尺波长，极佳的开阔地传播距离，穿透性较差，功耗小。319.5 MHz-36”Wavelength,good open air range,good structural penetration,good battery life./36英寸波长，空旷地带传播、穿透性和功耗均佳。900 MHz-8”Wavelength,great structural penetration,interfe
6、rence is also possible at 900 MHz,poor battery life./8英寸波长，穿透性极佳，干扰较多，功耗大。7GE SecurityTrainingAdventWireless Transmission无线传输To transmit information using RF a carrier and some type of modulation is required/利用RF传输信息，需要使用载波和某些调制技术Carrier-the specific frequency to carry the information/载波-使用特定的频率来携带信
7、息Modulation-the means of encoding information on the carrier frequency/调制-将编码信息处理并添加到载波上8GE SecurityTrainingAdventFrequency Bandwidth频宽Bandwidth-a measurable area that information is transferred within/带宽-一个传输信息的可测量的区域Receivers bandwidth must be as larger or larger than the transmitters bandwidth/接收
8、机带宽必须同发射机的带宽相同或大于发射机The closest the match the more reliable the RF path/二者越接近、越匹配则RF传输路径越可靠9GE SecurityTrainingAdventNarrow Band Advantages窄波段的优势Smaller System devices/更小的设备体积Longer Battery Life/更长的电池寿命More Reliable/更可靠Low Current Consumption/较低的电流功耗Quieter Frequency/频率更安静Penetrates Buildings Better
9、/建筑物穿透性较佳10GE SecurityTrainingAdventSAW vs Crystal 两种发生器对比Technologies used in receiving and transmitting information/指的是接收和发送信息采用的技术SAW refers to Surface Acoustic Wave and provides good frequency accuracy at a moderate cost/SAW意指声表面波技术，能提供良好的频率精确性和适中的成本Crystal,by using a quartz crystal provides the
10、 highest frequency accuracy at a slightly higher cost/石英晶体器件可提供更高的频率精确性，价格稍高11GE SecurityTrainingAdventDead Spots&Phase Nulls 盲点和零相位Filing Cabinets文件柜Foil Backed Insulation背衬金属膜的隔断Mirrors镜子Metal Ductwork金属管道Anything That Can reflect signals任何会反射信号的物体Multiple Signals That Reach The Receiver At The Sa
11、me Time Can Cause A Phase Null多路信号同时到达接收机会导致零相位发生12GE SecurityTrainingAdventReceiving Information接收信息Determines the overall range of the system/确定系统的接收范围Superheterodyne Receiver converts the carrier frequency to a lower one and filters out unnecessary noise./超外差接收机将载波信号转换为低频信号并过滤掉无用的噪音Spatial Divers
12、ity to help eliminate phase nulls&dead spots./空间分集技术有助于消除零相位和盲点Does Not respond To Noise Or Interference From Outside Sources/不会对外部噪音和干扰有反应13GE SecurityTrainingAdventLearn Mode Technology读取模式技术Unique ID number assigned to each device at the factory/出厂时每个设备已被分配唯一的ID编号During system programming the con
13、trol panel Learns the specific device(ID number)into its memory/主机编程时读取特定设备的ID至内存The device ID number is part of the 58-bit word data pack/设备的ID编号是58位射频数据包的一部分14GE SecurityTrainingAdventWhen A Sensor Transmits无线探测器发射时It tells the receiver it is an ITI transmitter/向接收机报告它是ITI无线设备Sends a sensor ID num
14、ber/发送探测器ID编号Tells the receiver what device type it is (Door/Window,Smoke,Motion etc.)/报告它的探测器类型Gives the status of the sensor/报告探测器状态Indicates a low battery if necessary/如有则报告电池低电压15GE SecurityTrainingAdventWhen A Sensor Transmits(Cont.)无线探测器发射时(续)8 rounds of data when sensor is activated/探测器触发时发送8
15、轮数据8 rounds of data when sensor is restored/探测器复位时发送8轮数据3 supervisory rounds every 64 minutes/每64分钟发送3轮受监视报告Sensors must check in within a prescribed amount of time to satisfy the panel/探测器必须在指定的时间内在主机签到16GE SecurityTrainingAdventIndividual Point ID独一无二的定位IDEvery sensor is its own zone,so/每个探测器占用独立的
16、防区，因此Dispatch the fire department to the exact room/消防人员会直达起火的房间Dispatch police to the exact entry/Service technician knows location of problem prior to service call/在用户拨打维修电话前，技术人员就已经了解问题所在17GE SecurityTrainingAdventWireless System Integrity无线系统完善Supervised-all devices report to the panel at a prog
17、rammed interval/受监视-所有设备按预设的间隔向主机发送报告Low Transmitter Battery-each device monitors its own battery and when low sends the appropriate signal to the control panel/低电压-每个设备监视自己的电量，发现低电压时发送对应信号给主机Sensor Contention-each device transmits on a different timing interval to prevent signals canceling each oth
18、er out./探测器争用-每台设备在不同的时间间隔发射以防止互相干扰而削弱信号18GE SecurityTrainingAdventSupervised Wireless受监视无线技术Sensors check in every 64 minutes/探测器每64分钟自检并向主机发送报告1-“Im working fine.”2-“My battery is low.”3-“Im open/closedA trouble condition is generated when a sensor has a problem./一旦探测器有问题，主机即报告探测器故障19GE SecurityTr
19、ainingAdventSensor Battery Life电池寿命Crystal devices are controlled by lithium batteries/Crystal型探测器使用锂电池Saw devices controlled by alkaline batteries/SAW类型探测器使用碱性电池Battery Life is consistent with device usage a crystal device will last 5-8 years and a SAW device 2-3 years/电池寿命一致性较好Crystal Long Life devices can last up to 20 years/Crystal长寿命型设备电池可使用20年20GE SecurityTrainingAdventSummary总结SAW and Crystal TransmittersLearn Mode Technology读取模式技术Optimum Radio Band(319.5 MHZ)最优的波段Spatial Diversity receiver空间分集接收机Narrow Bandwidth(Less Interference)窄带宽Fully Supervised devices完全受监视的设备
