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Nokia cellular
phones
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Cordless Phones. Included
in this section:
First Level Security ...each time the Handset of a cordless phone is placed in the Base Unit, a unique Digital Security Code is initialized. This code is randomly selected from over 65,000 possible codes. When cordless phones are being used, this Security Code is continually transmitted between the cordless phone Handset and Base Unit. Because the Security Code is random (and unique for each cordless phone), other cordless phones will not be able to access your conversations. Not only are your conversations secure, the cordless phone Base Unit is also secure from someone accessing your phone line to make unauthorized phone calls. Second Level Security ...fully Digital Transmissions between cordless phone Handset and Base Unit prevent unwanted interception. Most 900 MHz Digital cordless phones have been engineered to transmit all audio in an encrypted Digital Format. All transmissions between the cordless phone Handset and Base Unit are first filtered through Proprietary Digital Algorithm which converts the analog audio to a Digitally Encrypted code which consists of strings of ones and zeros (1's & 0's). Only the cordless phone knows the correct Algorithm to convert the Digital Code back into analog audio which you can understand. The process of Digitally Encrypting your cordless phone conversations has two benefits. First, the Digital Code being transmitted between the cordless phone Handset and Base Unit cannot be picked up by someone using another cordless phone or scanning device. This feature gives you the assurance that all conversations on cordless phones are truly secure. Secondly, Digitally Encrypting all cordless phone voice transmissions vastly improves the quality of sound. Static, hiss, and unwanted buzzing are virtually eliminated when using Digital Encryption. Spread Spectrum ...is a new technology in digital cordless telephones that enhances the security of your conversations even further! Cordless Phone Extended Range. Most conventional cordless phones on the market were designed to work in the crowded 46/49 MHz frequency band, all competing for limited resources which are shared with low-band pagers, radio remote controls, two-way walkie-talkies and "baby monitors". Cordless phones transmit in the 900 MHz frequency range. Using these more efficient 900 MHz frequencies, has succeeded in developing several cordless phones which perform at extended operating distances not possible in the 46/49 MHz band. Under ideal test conditions, 900 MHz cordless phones can perform at a range of up to five times these conventional 46/49 MHz band cordless phones. With the introduction of Spread Spectrum cordless phones, even better range can be expected. This is due to the fact that Spread Spectrum cordless phones are allowed to use more transmit power than equivalent fixed-channel cordless phones. Based on extensive feedback from customers, we have established that our 900 MHz cordless phones regularly perform at distances ranging from 2 to 5 times the conventional cordless phone range, which equates to 200 to 2,000 feet, depending on the operating environment. The primary differences between common 46/49 MHz cordless phones and cordless phones at 900 MHz are related to Wavelength and Signal Strength. The wavelength of a 46/49 MHz cordless phone transmission is 18 feet, while the wavelength of a 900 MHz transmission is one foot. The shorter wavelength 900 MHz cordless phone energy bounces off objects more efficiently (thus permeating an area more completely) and travels a greater distance than the 46/49 MHz cordless phone signal. Wavelength also determines the length of the antenna. The 18-foot wavelength of a 46/49 MHz cordless phone transmission requires a minimum antenna length of two- to three-feet long - or one-sixth the actual wavelength - to transmit from the cordless phone handset to base unit. On the other hand, digital cordless phones use a six-inch antenna - which is one-half the wavelength at 900Mhz. This "half-wavelength" design provides greater transmission efficiency and is more user-friendly. A 900 MHz cordless phone transmission also provides a stronger signal strength than the traditional 46/49 MHz cordless phone transmissions. Combined with the shorter, more permeating 900 MHz cordless phone wavelength and the more efficient half-wavelength antennas, this stronger signal strength results in increased range and performance. Cordless Phone Digital Technology. A 900 MHz digital transmission is produced by converting analog voice to a digitally-encrypted code. The digital transmission produces specific code patterns between the cordless phone handset and base unit, which can be transmitted and detected at a greater range than conventional 46/49 MHz analog cordless phones. 900 MHz digital cordless phones typically perform at three to five times the range of conventional 46/49 MHz cordless phone sets. Not only does a 900 MHz digital transmission provide greater range, but it also provides more uniform coverage within your operating area. Clarity is also a result of the cordless phone digital encryption process. When your voice is converted from analog to digital, only the actual sounds of your voice are encrypted; background noise and static, so common in 46/49 MHz analog transmissions, are eliminated. This process is similar to the audio heard on a digital compact disc as compared to an analog LP record album. The final and most timely benefit of 900 MHz digital transmissions is security. 900 MHz digital cordless phones offer two levels of digital security. The first is a function of the digital encryption process. When your voice is converted from analog to digital, the resulting digital code is scrambled in a way that only the handset and base unit are programmed to understand. The average cordless telephone user, short-wave radio hobbyist, or baby monitor owner will not be able to eavesdrop on your private conversations. The second security level is provided by a digital security code that is randomly generated from 65,000 possible codes each time the cordless handset is placed on the base unit. This code is continually transmitted between the cordless phone handset and base unit, preventing someone else from accessing your phone line, listening to your conversations or placing unauthorized phone calls. Cordless Phone Spread Spectrum. The primary difference between conventional Fixed Frequency cordless phones and Spread Spectrum cordless phones is multi-channel operation. A conventional cordless phone is designed to use only one channel (or radio frequency) at a time. Fixed frequency cordless phones will not switch to a new channel unless they encounter interference or if the user forces a channel change manually. Spread Spectrum cordless phones use multiple frequencies (or "channels") to transmit your conversation. This process is completely transparent to the user. The benefits of Spread Spectrum cordless phone transmission is due to this multi-channel format. A Spread Spectrum cordless phone "spreads" the signal across virtually the entire 900 MHz cordless phone bandwidth (between 902 & 928Mhz). This process ensures that your conversations are Secure, because only the cordless phone Handset and Base Unit know the pre-assigned spreading code, preventing someone from "locking on" and eavesdropping on your conversations. Spreading the transmitted signal over a very large bandwidth also provides improved Clarity, as this cordless phone technology circumvents traditional sources of interference in the first place. The third major benefit of cordless phone Spread Spectrum Technology is increased Range. The Federal Communications Commission (FCC) allows Spread Spectrum cordless phones to transmit at a higher power level than conventional, fixed-frequency cordless phones. The justification for increased power levels is a direct result of the multi-channel format. By allowing Spread Spectrum cordless phones to transmit at a higher power level, the potential exists for operating the handset at a greater distance from the cordless phone base unit than is normally possible. It is important to note that the actual range of
cordless phones (regardless of the technologies employed) is primarily determined by the environmental conditions where the
cordless phone is installed and being used. |
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