Abstract: A method for transmission of a digital information packet. A synch word of a packet header of the packet is transmitted from a transmitter to a receiver over a distorting channel. During transmission of the synch word, transmission is interrupted by at least one bit time of quiescence of the transmitter. The synch word is received at the receiver. Based on a channel distortion characteristic determined for the received synch word, a preferred sampling point is determined for succeeding bits of the packet.

Abstract: A method of providing local autonomous control of channel allocation of a cellular telecommunications network. In one prior art method, which can be identified as the timid method, a channel is selected for use by an incoming user if it is not being used by any of the cells which surround it. Otherwise, another channel is selected according to the same rule. The channels are tested in random order and a call is blocked if all of the channels are in use. For heavy loading, because of the vagaries of the way the demand for channels occurs, this method can result in inefficient channel deployment. In another method, which can be identified as the aggressive method, a channel is selected for use by an incoming user even if that channel is currently being used in the surrounding cells. If the channel is in use, the incoming user "bumps" the current user off the channel in the timid mode. The "bumped" user is then forced to find and use another channel.

Abstract: Improved side mode suppression with significantly reduced side mode suppression ratio fluctuation during laser tuning is realized in a distributed Bragg reflector laser structure by incorporating at least one reflector element which exhibits an asymmetric reflection characteristic versus wavelength over a band of wavelengths wide enough to include at least two longitudinal modes of the laser. That is, the asymmetric characteristic is wider than the mode separation for adjacent longitudinal modes of the laser. In one embodiment, a distributed Bragg reflector laser is shown wherein the Bragg reflector includes a corrugated waveguides with corrugations having a period which varies nonlinearly from .LAMBDA..sub.O at one end of the reflector to .LAMBDA.hd L at the opposite end of the reflector, where .LAMBDA..sub.O is greater than .LAMBDA..sub.L. Integrated and extended cavity or hybrid structures are described in both semiconductor and fiber laser structures.

Abstract: An optical equalization receiver for countering the effects of delay distortion is realized by utilizing dynamically controllable Fabry-Perot etalon structures. By dynamically adjusting the frequency response of an etalon that is in a feedback loop configuration, the associated delay characteristic of the etalon may be used to counter the effects of delay distortion, thereby allowing higher transmission rates and transmission distances to be achieved. In one exemplary embodiment, an optical receiver comprising a reflective Fabry-Perot etalon and a piezoelectric transducer is used in a feedback loop configuration wherein a feedback control circuit monitors an output signal from the etalon for generating a control signal representing the amount of delay needed to compensate for distortion in an optical signal incident on the etalon.