LV11509B - Method and apparatus for transmitting information - Google Patents

Description

LV 11509

METHOD AMD APPARATUS FOR TRANSMITTING INFORMATION

The invention relates to an assembly and method for accomplishing a radio contact 5 between two radio interfaces and transmitting information between these interfaces.

Transmission of information along a radio transmission path, e.g. through an obstacle, like a wall, may sometimes appear to be diffrcult, because a power of a mobile phone or base station is limited. This problem is illustrated in figurē 1. A communication is 10 tried to provide between the mobile phone 5 and base station 1, even the phone is situated behind some obstacle 9, there through the communication is now possible. Nowadays information is transmitted into or from indoors in the way illustrated in the figurē 2. Information is transmitted at a radio frequency from a base station 1, BS to an antenna 2 connected to a repeatēr 3 via a radio frequency cable 4. The repeater 3 is a 15 device, which automatically re-transmits signāls from one communication to another. Generally the repeater 3 is indoors in the case like this. The information is amplified in a radio frequency amplifier 6 of the repeater and transmitted to a hand-held telephone 5 indoors. The amplifier 6 is of broad-band type. The input electric power is distrib-uted into several channels whereby Ievels of the cālis at the amplifier may change. The 20 čabies 4 and 4a from the antennas 2 and 2A to the amplifier must be of radio frequency cable, hence the information transmission by this way is remarkably expensive. The call or another information is transmitted into the opposite direction correspondingly.

In order to solve this problem and to provide information transmission characteristic to 25 the method and assembly according to the invention is that what is presented in the characterising parts of the claims.

As the remarkable benefit of the invention can be considered that the information transmission expenses decreases. Previously known Standard circuit boards, which are 30 used in mobile phones, can be used as the devices. Hence the transmitter/receiver cir-cuits of the mobile phone, which are normai serial production components, can be benefited. The radio frequency is not necessary to transmit via the radio frequency cable through the obstacle. The communication betvveen the upper and lower parts of the repeater is possible to provide more economically than before.

The invention is described referring in the following to the drawing, wherein figurē 1 illustrates a principle figurē of the field of the problem, figurē 2 illustrates information transmission in accordance with the prior art, 35 2 figurē 3 illustrates a solution according to the invention ffom an embodiment, figurē 4 illustrates receiver and transmitter Solutions for a message transmitted from a base station. 5 There is illustrated in the figurē 3 an improvement to transmit a radio telephone message, when the message to be transmitted at a radio firequency is desired to transmit to a place which is not accessible by a normai base station use. In the follovving is de-scribed the message transmission into one direction. It is naturally evident that the message transmission into the opposite direction is possible and it is provided in a cor-10 responding way as into the opposite direction. A message at a radio frequency is transmitted from a base station 1 (BS) to an antenna 2 of an upper part 3a of a repeater. The upper part 3a of the repeater receives the message at the radio frequency and is capable to convert or demodulate the message away 15 from the radio frequency to an audio frequency, wherein the same is transmitted e.g. via a cable 7 into a transmitter at a lower part 3b of the repeater, a carrier wave is modulated and transmitted from the lower part of the repeater as a radio wave along a transmission path 8 to the hand-held telephone 5. 20 More precisely the repeater is formed of transmitter and receiver circuits of an NMT-telephone and comprises the upper part (master) and the lower part (slavē). For pro-tecting these circuits a casing or a corresponding is provided. A Central unit Controls the communication from the inner part to the outer part and vice vērsa and it is capable to recognise signalising commands by which the call is directed to receivers and by 25 which the repeater is controlled both is capable to convert a radio frequency to a audio frequency and vice vērsa.

The transmitting and receiving frequencies of the lower part of the repeater coire-sponds to the frequencies of the base station. Although the repeater composed of the 30 transmitter and receiver circuits of the NMT-telephone may lead to a power decreasing when transmitting, in most cases even a low power is adequate, because the spaces in-doors are limited.

Because the call is transmitted between the heads of the double sectional by means of 35 audio frequency, the wires to be used are economical. Therefore it is possible that by using a ramifier means from the .upper head or the master section of the repeater may extend several wires, the ends thereof are placed different rooms or spaces such, that the message can be transmitted to the desired Iocations. The solution according to the 3 LV 11509 invention in its simplest mode connects at mobile telephone traffic of firequency dis-tributed type only one call at a time. Depending on the number of cālis it is possible to choose a system of desired extent. The invention is especially preferred for a low density call connection. 5

Any copper cable, light cable, radio link or e. g. double wire connection can be used as the transmission path 7 between the upper and lower heads of the repeater. The re-peater must be capable to receive messages and to transmit the same further to the transmission path. The method may transmit mobile telephone traffic of time, code or 10 frequency distributed type.

It is possible to make the upper and lover heads of the repeater as modulē constructed, whereby also at the firequency distributed traffic the cālis are possible to connects at several channels. 15

In the figurē 4 there is illustrated in a more precise way a message transmission in one direction firom a base station to a mobile telephone. There is naturally a reason to State, that the message is possible to transmit into the opposite direction when reverse cir-cuits are in use. The message transmitted firom the base station 1 is transmitted, the 20 message is received at an upper head 32 of a repeater by a receiver Circuit, the message is converted to be of audio firequency type and the message is guided via tiie communi-cation path 7 between the lower and upper parts 3b, 3a to the transmitter Circuit 3b of the lower part of the repeater, while a speech of basie firequency modulates the radio frequency of the radio transmitter 3b the radio waves are transmitted to the receiver 5 25 of the mobile phone.

Especially there is the reason to notice that the invention is deseribed above referring to only one advantageous embodiment example thereof. However, the same is not in-tended by any means to limit the invention to concem just this example but several 30 modifications are possible within the scope of inventive idea defined in the following claims. 4 LV 11509

CLAIMS 1. Method, in which method information is transmitted between a base station (1) and radio telephone (5) by a repeater (3) along a transmission path, characterized in, that 5 between the base station (1) and the mobile phone (5) a radio frequency message is demodulated into an audio frequency message by a repeater (3a, 3b) existing at the transmission path, which repeater is capable to execute audio/radio frequency conver-sions and to transmit information thus converted along the transmission path to the subscriber, and which repeater includes two sections (3a, 3b) having the abobe men-10 tioned fimctions and an audio frequency connection (7) therebetween. 2. Method according to the claim 1, characterized in, that the information transferred over a radio interface is received by the repeater (3a, 3b), which is a radio re-ceiver/transmitter unit, the information is demodulated therein from radio frequency, 15 the demodulated information is transmitted along the transmission path (7) as a carrier £requency to another receiver/transmitter unit (3 a, 3b), while speech of basie fre-quency is modulating the radio frequency of the radio transmitter (3b, 3a) the radio waves are transmitted to the mobile phone (5). 20 3. Method according to the claim 1, characterized in, that via the repeater (3a, 3b) is transmitted frequency distributed information. 4. Method according to the claim 1, characterized in, that via the repeater (3a, 3b) is transmitted time distributed information. 25 5. Method according to the claim 1, characterized in, that via the repeater (3a, 3b) is transmitted code distributed information. 6. Method according to the claim 1, characterized in, that transmitting and receiving 30 ffequencies of the inner part (3b) of the repeater corresponds to the frequencies of the base station (1). 7. An assembly for transmitting information between a base station (1) and mobile phone (5) by a repeater (3) along a transmission path, characterized in, that there ex- 35 ist between the base station (1) and the mobile phone (5) a radio frequency message to an audio frequency message and an audio frequency message to a radio frequency message converting repeater (3a, 3b), which is capable to execute the audio/radio fre-quency conversions and to transmit information thus converted along the transmission 5 path to the subscriber, and which repeater includes two sections (3a, 3b) having the abobe mentioned functions and an audio frequency connection (7) therebetween. 8. An assembly according to the claim7, characterized in, that the audio frequency 5 connection is a radio link, copper or light cable or a couble of wires.

Claims (8)

1. A method for transmitting information via a repeater (3) between a central station (1) and a radio telephone (5) via a transmission path, characterized in that between the central station (1) and the mobile telephone (5) The radio frequency message is demodulated in a frequency message by means of a repeater (3a, 3b) in the transmission track, which can perform sound / radio frequency modifications and transmit the so converted information to the subscriber of the transmission path, the repeater having two sections (3a, 3b) with the above functions and the sound frequency connection (7) between them. 2. A method according to claim 1, characterized in that the information transmitted by the radio interface is received by the repeater (3a, 3b), which is a radio receiver / transmitter unit in which the information is demodulated from the radio frequency, the demodulated information is transmitted via the transmission path ( 7) as a carrier frequency to the second receiver / transmitter block (3a, 3b), while the speech signal carrier frequency modulates the radio frequency (3a, 3b) the radio frequency radio waves are transmitted to the mobile telephone (5). 3. A method according to claim 1, characterized by transmitting through the repeater (3a, 3b) frequency-expanded information. 4. A method according to claim 1, characterized by transmitting through the repeater (3a, 3b) the information that is expanded over time. 5. A method according to claim 1, characterized by transmitting through the repeater (3a, 3b) the code-expanded information. Method according to claim 1, characterized in that the transmitting and receiving frequencies of the repeater's internal part (3b) correspond to the frequencies of the central station (1). 7. The information transmission device between the central station (1) and the mobile telephone (5) in the transmission path by means of a repeater (3) is characterized in that there is a repeater (3a, 3b) between the central station (1) and the mobile telephone (5). , which converts a radio frequency message into a sound frequency message and a sound frequency message in a radio frequency message and is capable of performing a sound / radio frequency conversion and thus transmitting the converted information to a subscriber of a transmission path, the repeater having two sections (3a, 3b) with the aforementioned functions and a frequency frequency connection between them. Device according to claim 7, characterized in that the sound frequency connection is a radio communication line, copper or light cable or wires.