Wireless optical communication system with adaptive data rates a

Details Wireless optical communication system with adaptive data rates a Wireless optical communication system with adaptive data rates a

1996-09-03

1998-09-15

Negash, Knife-Michael

Optical: systems and elements

Deflection using a moving element

Using a periodically moving element

359172, 34082572, 371 201, H04B 1008

Patent

active

058087605

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to a wireless optical communication system for data transmission.


BACKGROUND OF THE INVENTION

With the rapidly increasing number of workstations and personal computers (e.g. desktop or handheld ones) in all areas of business, administration, fabrication etc., there is also an increasing demand for flexible and simple interconnection of these systems. There is a similar need as far as the hook-up and interconnection of peripheral devices, such as keyboards, computer mice, printers, plotters, scanners, displays etc., is concerned. The use of electrical interconnects becomes a problem with increasing number of systems communicating with each other, and in many cases in which the location of systems, or the configuration of subsystems, must be changed frequently. It is therefore desirable to gain flexibility and thus to eliminate electrical interconnects for such systems and to use wireless communication instead.
The use of optical signals for wireless transfer of digital data between systems and devices has received increased interest during recent years and has lead to applications in commercial products. One example is the optical remote control of electronic instruments. In the Patent Abstract of Japan of the Japanese Patent JP-A 5145975, No. 535 (E-1439), a conventional remote control system is disclosed. This remote control determines the amount of ambient light and sends out stronger signals if the ambient light level is high. If the ambient light level is low, it transmits signals with reduced power. Another example is the communication between information systems in an office environment. Digital data to be transferred between a transmitting system and a receiving system are transformed to modulated optical signals which are radiated from a light source--in particular an infrared (IR) one--at the location of the transmitting system and are received and converted to electrical signals and then to digital data by the receiving system. In the Patent Abstract of Japan of the Japanese Patent JP-A 4256234, No. 35 (E-1310), an optical transmission system is disclosed. It comprises a receiver and transmitter being connected via feedback means. These feedback means are employed to control the level of input current driving the light sources on the transmitter side. I.e., the system disclosed is a communication system where the output power of the transmitter is controlled and adjusted to ensure that the burden of the light sources is reduced. The optical signals might directly propagate to the optical receiver of the receiving system or they might indirectly reach the receivers after changes of the direction of propagation due to processes like reflections or scattering at surfaces. Today, the former case is realized in docking stations for portable computers where the data transfer takes place between an optical transmitter and a receiver which are close together at a distance on the scale of cm and properly aligned. The latter case is typical for applications in an office environment in which undisturbed direct transmission of optical signals between transmitters and receivers several meters away from each other is unpractical or even impossible due to unavoidable perturbations of the direct path. One known approach to achieve a high degree of flexibility is to radiate optical signals from the transmitting system to the ceiling of an office where they are reflected or diffusely scattered. Thus, the radiation is distributed over a certain zone in the surroundings of the transmitter. The distribution of the light signals spreading from the ceiling depends on many details which are characteristic for the particular environment under consideration. However, essential in this context is mainly that the transmission range, i.e. the distance between transmitting system and receiving system, is limited to some final value, hereafter called the transmission range, since the energy flux of the transmitted radiation decreases with increasing distance of propagation and

REFERENCES:
patent: 5623355 (1997-04-01), Olsen
patent: 5652668 (1997-07-01), Aulet et al.

Affiliated with

Also associated with

Rating

Wireless optical communication system with adaptive data rates a does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Wireless optical communication system with adaptive data rates a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wireless optical communication system with adaptive data rates a will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-94014