| 2.4 GHz wireless technology unlimited, cable-free reliability
Wireless technology for the transmission of input signals to the computer has developed in leaps and bounds over the past few years. From infra-red and 27 MHz technology, right through to 2.4 GHz wireless technology - the transmission reliability, range and, last but by no means least, energy efficiency of wireless products has been improved continuously.
The development of wireless technology continues to be pushed forwards by a number of manufacturers working towards the same goal to free the desk of cumbersome wires, without having to compromise on speed and reliability during transmission.
Whether mobile phones, PDAs or laptops - wireless products are being used ever more frequently in modern day society. Mobility is essential, even at the desk at home or in the office. In addition to the aesthetic advantages afforded by a wireless work space, physical comfort also plays a major role. People who use wireless input devices are able to move more freely and are less restricted. They can change their sitting position more frequently and, with a hydraulically adjustable desk, can even alternate between sitting and standing. These advantages play a major part in helping to combat RSI (Repetitive Strain Injury) syndrome.
Negative experiences in the past have prompted many users to return to the restrictive corded models. When several desktop keyboards were used in the same room, the text from the neighbouring computer would often suddenly appear on the screen or signals would be lost completely on the way from the keyboard to the screen. The battery power consumption for the first generation of wireless products was also enormous.
1.) The evolution of wireless technology - from infra-red technology to the "next generation"
The first wireless products used infra-red technology to transmit signals. This was the first step towards wireless freedom. However, the products still had the disadvantage that the user had to maintain constant "visual contact between the transmitter and the receiver. The mouse had to be held precisely in the direction of the corresponding receiver for transmission to be successful. Transmission rates were also considerably lower than those achieved with corded devices.
The next development stage used a tried-and-tested principle of wireless signal transmission radio technology. The same technology used for radio and TV transmission proved to be extremely effective for the transmission of data between a wireless periphery device and its receiver.
This transition to 27MHz technology meant that the user no longer had to maintain direct contact between the transmitter and the receiver. It was also possible to send larger quantities of data over a greater distance between the transmitter and receiver.
Although this was without a doubt a major improvement compared with infra-red technology, some aspects still left room for improvement. Particularly with regard to transmission speed, latency period and energy consumption, the developers were still working to increase performance further. This was achieved by changing the frequency from 27MHz to 2.4 GHz.
2.) 2.4 GHZ the ideal frequency for problem-free operation of wireless devices, with no interruptions
Delays between inputting a signal on the keyboard or mouse and the output of the signal on the screen were often a major cause of frustration when working with wireless periphery devices. 2.4 GHz wireless technology ensures problem-free transmission of even large quantities of data with no time delay. And how is rapid transmission guaranteed?
The data packets sent from the periphery devices are sent as waves to the receiver in the same way as radio and television signals. These data packets contain usage information, encryption data, error correction and comparison information for transmitter and receiver. Individual details are outlined in section 3.
The larger bandwidth compared with the 27 MHz frequency enables larger quantities of data to be sent in shorter time intervals. The transmission rate for 27 MHz products lies between 20 and 50 kilobits/sec. 2.4 GHz technology from Cherry reaches up to 1000 kilobits/sec.
The latency period waiting time between signal input and output on the screen - is therefore reduced considerably. Time delays between the signal input and output on the screen are a thing of the past.
There is no reduction in transmission reliability. On the contrary, this "Achilles heel" in the previous procedure for wireless signal transmission has been practically eliminated through the use of a range of additional technology.
3.) Frequency hopping and ID comparison (pre-coding) the highest possible transmission reliability
The high bandwidth of the 2.4 GHz frequency enables signals to be distributed into several channels - an advantage which is not possible with the 27 MHz frequency.
In exact figures: the frequency range of 2.4 GHz technology lies between 2.400 GHz and 2.4835 GHz and is therefore 83.5 MHz. The frequency range of 27MHz technology lies between 26.957 MHz and 27.283 MHz and is therefore 0.326 MHz (1 GHz = 1.000 MHz).
The 2.4 GHz frequency range could theoretically be distributed between any number of channels to ensure transmission reliability. Excessive splitting would, however, lead to an extremely low width of the individual channels, which, in turn, would reduce the transmission rate considerably. 2.4 GHz Cherry products transmit on 32 channels and guarantee absolute transmission reliability with maximum transmission speed. So why do more channels help to increase reliability?
From the 32 selected channels of the 2.4 frequency wave, 2 channels are used for the function known as channel hopping. During production, each 2.4 GHz product is allocated a specific channel pair. During use, desktop A may transmit on channels 1 and 17, for example, while desktop B transmits on channels 16 and 32. The transmission "jumps" constantly from one frequency to the other (frequency hopping). There is a 1:16 probability that two keyboards will transmit on the same channels within their transmission range.
In an open plan office, however, problems can still occur even with a probability of 1:16. Cherry therefore equips all 2.4 GHz products with a second safety system. Periphery devices and the corresponding receiver are given an ID code as early as the production stage. During this process known as pre-coding, 2 to the power of 24 ID- codes are allocated. This results in over 16 million ID codes. Each receiver only accepts information from the device with the same ID code. Signals from keyboards or mice with a different ID are not decoded. The combination of frequency hopping and the allocation of ID codes reduces the probability of disturbance being caused between two periphery device to next to nothing.
The term "precoding" points to an additional function of the ID comparison. The automatic allocation of ID numbers during the production process means that products no longer have to be connected to each other manually before using them for the first time. Previously, the small connect buttons on the underside of the receiver and transmitter had to be pressed alternately for a few seconds using a pointed object. Although this ensured transmission reliability between the two devices, this method also opened up a number of potential error sources. Many users, for example, would activate the connect buttons after the first commissioning, but forgot to re-establish the connection following a battery change. They then had to turn to the service hotline to solve the problem.
4.) 2.4 GHz technology transmits, and transmits, and transmits....
A sudden break in the power supply during work is not only inconvenient - frequent battery changes, particularly in large companies, can also be extremely expensive. In order to ensure the lowest possible energy consumption, all 2.4 GHz Cherry products are equipped with state-of-the-art CMOS technology. The width of the channel used to transmit the data packets also plays an important role with regard to the power supply. The channels of the 27 MHz frequency are significantly narrower compared with the 2.4 GHz frequency wave. This means that the data packets have to be sent continuously, resulting in constant energy consumption. The shorter length of the waves and the larger bandwidth, combined with the use of CMOS technology, help to reduce the amount of energy consumed by a wireless keyboard from around 20 milliampere with 27 MHz technology, to as little as 3 milliampere for transmissions with 2.4 GHz technology.
5.) The range of 2.4 GHz technology as far as the eye can see, and further...
The shorter wavelength enables a much larger range than can be achieved with 27 MHz. Wireless keyboards and mice which send data packets with 2.4 GHz technology achieve a range of 10m and more. 27 MHz wireless periphery devices usually stop at 2m. Cherry products equipped with 2.4 GHz guarantee transmissions at ranges up to 10 meters with no interruptions. This opens a up range of new possibilities for the user. During a presentation, new pages can be called up with the mouse from a range of distances. MultiMedia functions on the computer can be controlled from the comfort of the couch.
Products with 2.4 GHz technology are the current reigning champions in the field of wireless computer input devices. Cherry was the first in the market to launch a keyboard with 2.4 GHz at the end of the 1990s. This longstanding wealth of experience now forms the basis for all our wireless keyboard and desktop models. With the universal introduction of 2.4 GHz technology for all new wireless desktop models, Cherry is opening up the latest wireless technology for every product and price range.
All desktops available from 2007 in the eVolution "next Generation" range are wireless and transmit with 2.4 GHz frequency - from starter products and the SIRIUS XT Wireless MultiMedia Desktop, right through to the ORCA Wireless Design Desktop.
|
select language: 
