Abstract: This invention relates to duplex and to half duplex transmission schemes and more particularly to the application of such schemes in TDMA and other multiple access environments. In accordance with a first aspect of the invention, there is provided a method of multiplexing signals transmitted by a number of terminals onto a communications link; the link having a capacity less than the total capacity of the terminals; the method including the step of varying the rate of encoding of said signals transmitted by said terminals whereby the bandwidth o the transmitted signals corresponds to the portions allocated to the terminals. In accordance with another aspect of the invention, there is provided a system for the communication of signals in real time over a channel; said system adapted to vary the bandwidth of at least one signal such that the number of signals multiplexed onto said channel can be dynamically varied.

Abstract: Process for forming a selectively colored polymeric layer, or a three-dimensional article made of polymeric layers, wherein a photocurable, photocolorable composition is irradiated with a low dose of light to cure and a different, preferably higher, dose of light to color. The process is particularly useful for preparing selectively colored ornamental and industrial articles and models of plant and animal parts, especially medical models.

Abstract: A radio access system comprises a base station and a plurality of subscriber locations. The subscriber locations each comprise a residential base unit or subscriber interface which includes line termination equipment. A group of subscribers is served by a pool of residential radio transceiver units in radio communication with the base station which is connected to the residential base units by a shared bus. A group of subscriber locations may be served by a lesser number of residential transceiver units, while at the same time providing individual locations with access to increased bandwidth for ISDN services and the like. Also described is a system in which a subscriber's base unit is connected to two or more residential transceiver units to allow increased bandwidth without requiring additional residential base units.

Abstract: This invention relates to radio communications and in particular relates to a method for allocating channels in a radio communications system having a plurality of bearers in a system which is subject to slow temporal fading. In radio communications, signals are transmitted at a particular frequency, in a frequency band or in a number of frequency bands. Obstacles in a signal path, such as buildings in built-up areas and hills in rural areas, act as signal scatterers and these, together with fading, amongst other factors can cause signalling problems whereby signals may not be communicated on certain channel The present invention provides a system and method for channel allocation method for a multi-bearer communications network, with each bearer supporting a number of channels, wherein after allocation of a channel responsive to an access request from the available bearers which can provide access, the maximum number of available slots are left on each bearer, for a particular level of subscription.

Abstract: A fixed wireless access communication network is described. The capacity of a fixed wireless access network is limited by the number of radio frequencies and hence the numberof channels available. The present invention prepares a solution to this problem whenever the radio channels are transmitted at one of at least two power levels.

Abstract: This invention relates to radio communication systems and in particular relates to a method of installation for a fixed wireless access subscriber antenna. According to one aspect of the present invention there is provided a method of installing a fixed wireless access arrangement comprising one or more directive antennas operable to be directed at a base station; the method steps comprising: determining the absolute position of the location of the subscribers premises employing a radio position determining receiver; referencing data relating to the absolute position of the location of a fixed wireless access base station; positioning an antenna relative to the base station given the absolute position of the whereby initial set-up of the antenna is sufficiently accurate whereby fine tuning of the antenna is possible. By configuring the antenna mount prior to attachment on the structure, then the time required to deploy fixed wireless access subscriber equipment is much reduced.

Abstract: An antenna arrangement (10) for a cellular radio base station is provided with a plurality of r.f. transceivers, including one or more antenna arrays (12) each comprising a plurality of sub-arrays (20) each selectively operpable to form a beam in azimuth. Each sub-army is provided with elevation beamforming means (24) and individual transmit and receive amplifiers (30,32). Each sub-array beamformer is coupled to at least one r.f. transmitter feed (26)nd each r.f. receiver feed is coupled to at least two sub-array beamformers, the sub-arrays of each antenna array together forming a multiplicity of separate substantially coincident beams in azimuth. A method of operation is also disclosed.

Abstract: An isolation work station comprising an enclosure, and an air circulation system and high efficiency air filter for generating a downwardly directed laminar air flow through the enclosure. Periodic sterilization of the enclosure may be accomplished by adding a sterilant, such as vaporized hydrogen peroxide, to the airstream, and the filter is impregnated with a catalyst for degrading the vaporized hydrogen peroxide during the purge cycle and wherein the airstream is circulated at a relatively low speed so as to increase the residence time in the filter.

Abstract: An improved extractor housed in the breech of a firearm for extracting a metallic cartridge case from a firearm including a U-shaped cap connected to a bore wall of the breech of the firearm; an extractor body and a biasing means for exerting tensile force on the extractor body whereby said gripping end of the extractor body is forced into a gripping relationship with the rim of a metallic cartridge case to be extracted.

Abstract: In methods and apparatus for providing communications to a telecommunications terminal, a request for a page of data is received at a data service node, the request specifying at least one particular terminal. A terminal status request is sent from the data service node to a communications system which serves the particular terminal, the terminal status request specifying the particular terminal. The data service node receives from the communications system a terminal status message containing information indicating a current status of the particular terminal. The data service node sends to the data terminal a page of data indicating the current status of the particular terminal. The page of data comprises a communications request icon when the particular terminal is in a state in which it can communications.

Abstract: An antenna arrangement comprising at least 4 upright omnidirectional antenna is disclosed. The omnidirectional antennas are spaced apart in an irregular fashion. By providing at least 4 omnidirectional antenna in a irregular spaced apart arrangement, spatial diversity is provided, at any distant point from the antennas, by at least 3 antennas. Thus the minimum gain, for a four antenna arrangement, approaches 0.75 of the maximum gain when taking relative position of a receiver into account.

Abstract: A method for producing aromatic amines such as N-phenyl-p-phenylenediamine is disclosed wherein an amine substituted aromatic such as aniline is oxidized with oxygen or hydrogen peroxide in the presence of trisodium pentacyano ferrate(II) complexes containing various water soluble ligands, such as ammonia, mono alkyl amine, dialkyl amines, and trialkyl amines. The complex is subsequently catalytically reduced by hydrogenation using certain heterogeneous metal catalysts to yield the desired aromatic amine.

Abstract: This invention relates to radio communication systems and provides a signal combiner for a radio communications system having a number of receiving antennas. The signal combiner receives signals from all receiving antennas and provides a combination technique with performance close to optimal (maximal ratio) combiners but without the complexity. The invention provides a base station (10) arrangement which only processes the outputs from antennas (12) which contribute positively to the overall system carrier-to-noise ratio.

Abstract: A synchronous voice/data messaging system allows parties to communicate both voice and graphic information or other data interactively or to retrieve such information synchronously in the exact sequence in which it was created. Voice information and data information are transmitted on a voice channel and a data channel. Time stamps are generated to synchronize the voice and data information. The time stamps can be generated either in a user device or in a multimedia messaging system. In either case, the voice and graphic or other data is played back to the called party in the exact sequence and at a rate corresponding to the rate at which it was received. Such a system can also be used to provide other services such as synchronous voice/data messaging while on hold or as part of a multimedia greeting.

Abstract: A method for producing aromatic amines such as N-phenyl-p-phenylenediamine is disclosed wherein an amine substituted aromatic such as aniline is oxidized with oxygen or hydrogen peroxide in the presence of trisodium pentacyano ferrate(II) complexes containing various water soluble ligands, such as ammonia, mono alkyl amine, dialkyl amines, and trialkyl amines. The complex is subsequently catalytically reduced by hydrogenation using certain heterogeneous metal catalysts to yield the desired aromatic amine.

Abstract: An isolation work station comprising an enclosure, and an air circulation system and high efficiency air filter for generating a downwardly directed laminar air flow through the enclosure. Periodic sterilization of the enclosure may be accomplished by adding a sterilant, such as vaporized hydrogen peroxide, to the airstream, and the filter is impregnated with a catalyst for degrading the vaporized hydrogen peroxide during the purge cycle and wherein the airstream is circulated at a relatively low speed so as to increase the residence time in the filter.

Abstract: Processes of preparing para substituted phenylamines, such as, p-phenylenediamines, and particularly, p-aminodiphenylamine. One process involves contacting phenylhydroxylamine with a nucleophilic reagent, such as aniline, in specified proportions and within a specified temperature range, in the absence of oxygen, and in the presence of a homogeneous acid catalyst, such as hydrochloric acid. A second process involves contacting phenylhydroxylamine with a nucleophilic reagent, such as aniline, in the presence of a solid acid catalyst, such as acidic zeolite Y, under reaction conditions.

Abstract: A truck bed liner has a plurality of slot pairs spaced around the top of the vertical walls of the liner at a level just below the interior flange of the truck bed walls. Resilient retainer clips engage the flange of the truck bed walls and secure the liner to the bed through the slot pairs.

Abstract: A system for forming substantially diamond-shaped gussets to be used in the production of panty hose garments wherein the gussets are formed by severing a circular knit tube along a bias angle of approximately 30.degree. subsequently to form strips having a width corresponding to the desired width of a gusset. The strip then is severed along a prescribed angle of approximately 30.degree. to define a gusset wherein the fabric wales extend parallel to a line extending from one point to the diagonally opposite point of the diamond-shaped gusset. The gusset is then transferred and oriented for subsequent sewing to hosiery blanks in the forming of panty hose.