LT4204B - Assembly and method for transmitting information - Google Patents

Assembly and method for transmitting information Download PDF


Publication number
LT4204B LT96-078A LT96078A LT4204B LT 4204 B LT4204 B LT 4204B LT 96078 A LT96078 A LT 96078A LT 4204 B LT4204 B LT 4204B
Prior art keywords
intermediate amplifier
base station
Prior art date
Application number
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Lithuanian (lt)
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LT96078A (en
Jouko Rautio
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Finland Telecom Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to FI955179A priority Critical patent/FI955179A0/en
Application filed by Finland Telecom Oy filed Critical Finland Telecom Oy
Publication of LT96078A publication Critical patent/LT96078A/en
Publication of LT4204B publication Critical patent/LT4204B/en



The invention applies to the field of telephone communication and the method and device described are intended for creating a radio communication and information transmission between two communication means. The object of the invention is a communication between a base station (1) and a mobile phone (5), when the base station coverage zone is insufficient. Communication is realised by converting the radio frequency signal while transmitting in the first part of the interim amplifier (3a) into a sound frequency signal, the one which is later, in the second part of amplifier (3b), converted into a radio frequency signal and transmitted to the subscriber's mobile phone (5).


The invention relates to the field of telephone communication and describes a device and a method for establishing radio communication and transmitting information between two means of communication.

The present invention differs from those described in WO 92/13400, US 4,698,805 and US 4,941,200 in that radio channel information is demodulated in one part of the intermediate amplifier, demodulated basic frequency information (usually in speech) is transmitted to the second part of the intermediate amplifier, and is modulated for transmission by radio channel. This allows the two different parts of the intermediate amplifier (in practice, the antennas) to be spaced far apart. This demodulation-transmission-modulation process is not described in any of the above publications, although changes in signal frequencies are provided. The use of this process in the intermediate amplifier provides various manufacturing, assembly, and application advantages over prior art intermediate amplifiers and communication techniques described in the above publications. Frequency switching to another radio frequency alone does not provide the benefits of the present invention.

In the context of this patent application, voice frequencies are understood to mean normal human speech frequencies within the range of 0.3-3.1 kHz for transmission over a public telephone network. The radio frequencies include the frequencies between 100 kHz and Ι Thz commonly used in telephone communications, particularly the frequency bands for the cellular telephone system by international frequency allocation: 118-174 Mhz [including ARP ™ (Vehicle Radiotelephones), Kaekohaku ™ system), ERMES (European Radio Messaging System)], 430-470 Mhz [including NMT 450 (Nordic Mobile Phone System 450), Autonet ™], 840-960 Mhz [including CT (cordless phones), NMT 900 (Nordic 900 cellular telephone system), GSM (Global Cellular Telephone System)] and 1.6-1.9 Ghz [including TFTS (Thyristoric Telephone System), DECT (Digital European Cordless Telephone), PCN ( personal communication network)].

With regard to the above publications, the differences between the English terms need to be highlighted. Unlike the Pan-Nordic NMT system, radio channels used in the AMPS North American radio system are assigned to channels that act as mediators in the flow of audio or other data and, on the other hand, to channels that include call set-up, call cancellation and appropriate system alarms and which cannot be adapted to the flow of audio or other data. Accordingly, the first mentioned channels for the movement of the audio stream are called "voice channel" in English and the frequency band dedicated to these channels is called "voice band". This suggests that this is unrelated to the normal speech band (i.e. 0.3-3.1kHz), which is commonly referred to as the "audio band" and hence the "audio frequency", abbreviated as "GD". The abbreviation GD is also used in the accompanying drawings to refer to the audio frequencies used in the telephone network. Europeans use the term "information channel" instead of "voice channel". Intermediate frequency mentioned in these publications, abbrev. TD, is the 455 kHz radio frequency on which many radios operate. It should be noted that in radios where the signal is transmitted at an intermediate frequency, the radio frequency is also modulated. Modern cable television systems (CTVs), which are used in various parts of the world, use radio frequencies between 50-900 MHz. It is worth noting that these frequencies overlap with those of cellular phones, but this is possible because radio waves are transmitted not by open space but by cable. This transformation of RD-RD into CTV frequencies is described in WO 92/13400. It is also important to clarify the North American terms "wired line" and "wired line operator". These terms are administrative-legal but not technical in terms of ownership of mobile telephone networks. A "landline operator" is a mobile telephone operator which is also the operator of a traditional fixed telephone network. The terms originate in the US policy of multiple licenses covering the same area, and usually one of the licensees is a local telephone company.

The accompanying drawings illustrate the differences between the present invention and the solutions according to the above publications. The abbreviations mentioned above are used. For clarity, only the radio section of the cellular telephone network is shown in the drawings.

Fig. 1 illustrates a normal situation in which a cellular telephone is on a highway and the radio frequency signal can move freely forward from the base station (BS) antenna A to the cellular telephone antenna B. This is a two-way communication, with corresponding transmission from the cellphone to the base station, but for the sake of clarity, this and other figures show only a one-sided relationship.

Figure 2 illustrates a typical problem situation where radio communication is obstructed by an obstacle on the radio path A- »B. The typical situation presented in the publication as an example arises when the cell phone is indoors with walls and other environments made of reinforced concrete and earth. Enclosed areas, such as car garages, can be set up a few meters underground. The obstacle can be any factor that absorbs the radio signal in such a way that no communication between the base station and the mobile phone becomes possible. In fact, even a long distance suppressing a signal in free space can be an obstacle.

Figure 3 shows a solution to the problem of the situation of Figure 2. Two radio links A—> C and D— »B are established. The intermediate amplifier consists essentially of an amplifier which amplifies without any modifications (e.g., without demodulation) the radio frequency signal coming from cable C- »V from antenna C and transmits it further via cable V—> D to antenna D from which it reaches the mobile. telephone B. The intermediate amplifier portion V may be located either upstream or behind the obstacle, but nevertheless the length of the cable C -> V or V_ »D must be such that the signal is transmitted through the obstacle. Because, for example, a cellphone in an underground room has to go a long way with a C-> V or V-> D cable (as mentioned, even a few meters), it is so suppressed that the intermediate amplifier cannot even be used. In addition, cables must be thick and heavy to reduce signal attenuation, making them very expensive to install and perform other installation work.

Fig. 4 shows a connection between an intermediate amplifier and a cell phone according to the state of the art according to the present invention. In this case, there are also two radio links A-> C and B- »D. The interleaver used here differs from the ones in the art in that the useful information, usually speech, in the interleaver part E preceding the obstacle is demodulated from the radio frequency signal to the voice frequency signal and transmitted through the interleaver to the interleaver part F which mentions the voice. frequency modulates the transmitter of part F and transmits the radio frequency signal to the mobile phone B. Unlike a conventional interleaver, the interleaver of the present invention requires a part controlling the radio signal both upstream and downstream of the obstacle (parts E and F). The voice frequency signal passes through an obstacle, whereby a cheap cable can be used for transmitting the voice frequency signal, and at the same time the installation and cable installation costs are reduced compared to the case shown in FIG. The radio frequency used in radio path D- »B may be the same as that used in radio path A-» C, but if the intermediate amplifier has a logical part, the radio frequency in path D—> B may be set regardless of radio path A-> B. C. It is, of course, believed that the obstacle suppresses the radio transmission D- »B so severely that no interference occurs in the radio network before the obstacle.

Figure 5A illustrates the situation described in WO 92/13400. For the sake of clarity, only the most important points are taken for comparison. FIG. 5B illustrates a solution to the situation of FIG. 5A, respectively. Unlike the situations shown in FIGS. 3 and 4, only one radio link A-B is formed here, corresponding to the normal situation shown in FIG. There is no intermediate amplifier at all. The fundamental difference is the distance between the base station and its antenna and the way in which the radio signal is transmitted between them. Under normal circumstances (fig. 1), the cable length from the base station radio transmitter to the antenna is several to several meters. In the case illustrated in Fig. 5B, this distance can be significantly larger, since a different transmission path is used, and the distance G-H can be overcome by a suitable radio frequency transmission system. The benefit of our invention is the lower cost of using some kind of complete RF transmission system, for example, in a closed room, a cable TV network entering the house.

However, such transmission takes place again using the radio frequency and without the demodulation operation-modulation process. Similar attenuations are also associated with this radio frequency transmission and so on. The problems sought to be avoided by our invention, and therefore, to solve these problems (in practice, at the expense of increasing costs), the amplifiers shown in FIG. 5B are required. The number of amplifiers, of course, depends on the number of connections.

Fig. 6 illustrates a method of using an intermediate amplifier according to US 4,941,200 to solve the problematic situation shown in Fig. 2. For clarity only the two-way intermediate frequency TD is shown inside the intermediate amplifier. Comparison of Figures 6 and 3 shows a completely similar nature of radio wave penetration through the obstacle. In contrast to the present invention, the intermediate amplifier receives a radio frequency signal, in which the radio frequency signal is demodulated to a voice frequency, transmitted through an obstacle and again modulated to the radio frequency. The use of intermediate frequency TD (and thus radio frequency) to amplify the signal in the conventional, common technique has the advantage that the amplifier and other parts that are connected to a weak (unimproved) signal can be tuned in this way better than if they were the coming broadband frequencies. In this case, attention is paid to frequency conversion and is based on US 4,941,200, where information is transmitted between different parts of an intermediate amplifier. It should be noted, however, that in this case, there is a clear difference between the US 4,941,200 patent and our invention, since in US 4,941,200 the intermediate frequency switching is normally used to amplify and change the signal to another radio channel; transmission in this form. It should also be noted that in this regard, there should be no difference between the technical means described in U.S. Patent 4,941,200 and the common technical means, but physical signal transmission should take place at intermediate frequency TD (not even mentioned in the publication where the intermediate amplifier is described as physical entity), since even in this case the transmission should be done at modulated RF frequency, so that the same problems of attenuation, etc., exist for the normal intermediate amplifier shown in FIG. There is the same difference between the spacer amplifier described in the present invention and that already used in common technical applications as between our application and the US 4,941,200 patent.

The illustration of U.S. Patent No. 4,698,805 is very similar to that of FIG. 1 and will not be discussed here. In connection with this, it is advisable to note the terminological differences in the English language used in the US, where the base station associated with the telephone network is called a "proxy amplifier", whereas, in the case of FIG. 3, the term is used to describe a proxy amplifier In the US, the term "Base Station" (BRS) is also used to refer to a base station). There is only one radio link in U.S. Patent 4,698,805. The solutions related to this patent are mainly for the distribution of the information flow with respect to the base station and are not at all consistent with the improvements provided by our invention.

Radio transmission of information over an obstacle such as a wall can sometimes be difficult due to the limited power of the cell phone or base station. This situation is illustrated in FIG. An attempt is made to establish a connection between the cellular phone 5 and the base station 1. Even if the cellphone is behind an obstacle 9, communication is possible in this case. Nowadays, information is transmitted to and from inside in the manner shown in FIG. Radio information is transmitted from a base station (BS) 1 to an antenna 2 connected to a radio frequency cable 4 by an intermediate amplifier 3. An intermediate amplifier 3 is a device that automatically transmits signals from one connection to another. Usually the intermediate amplifier 3 is inside. The information is amplified by the Intermediate Amplifier Radio Frequency Amplifier 6 and transmitted to the interphone 5. Amplifier 6 is broadband. The input power is distributed to several separate channels, so the call levels in the amplifier may vary. The cables 4 and 4A from the antennas 2 and 2A to the amplifier must be radio frequency cables, so the transmission of information in this way is quite expensive. The invitation or other information in the opposite direction is transmitted accordingly.

The problem solving and information transmission characteristics of the device and method of the present invention are set forth in the preamble of the invention.

A significant advantage of the present invention is that it reduces the cost of transmitting information. Previous standard line switches used in cell phones can be used as devices. This means that cell phone transmitter / receiver lines, which are normal serial production components, can be used. Radio frequency is not required to transmit information through an obstacle using a radio frequency cable. The connection between the upper and lower parts of the intermediate amplifier is much more economical than before.

The invention will now be described with reference to the drawings, in which:

Figures 1, 2, 3, 5A, 5B, 6 show a prior art.

Figure 4 illustrates one embodiment of the problem solving according to the present invention.

Fig.7 graphically depicts the root of the problem.

Fig.8 shows the transmission of information according to the prior art.

Figure 9 illustrates a solution to the problem of the present invention.

Fig. 10 shows the positions of the receiver and the transmitter when information is transmitted from the base station.

Fig. 9 illustrates an improved method of transmitting information where it is desired to transmit a radio message to a location that cannot be accessed directly from the base station. The following is a unidirectional way of transmitting information. It is quite obvious that it is possible to transmit information in exactly the same way in the opposite direction.

Radio information is transmitted from base station 1 (BS) to antenna 2 in the upper part 3a of the intermediate amplifier. The upper part 3a of the intermediate amplifier receives the radio information and can convert or demodulate it to the audio frequency at which the information is transmitted, e.g. by cable 7 to the transmitter lower part 3b of the intermediate amplifier, the carrier wave being modulated and transmitted by radio intermediate lower part transmission path 8 to phone 5.

The intermediate amplifier consists of the NMT telephone transmitter and receiver circuits and has an upper (command) part and a lower (executive) part. These contours are protected by a housing or similar. The central unit controls the communication from the top to the bottom and δ

vice versa, and can recognize signal commands that direct information to receivers and control the intermediate amplifier, both parts can convert radio frequency to audio frequency and vice versa.

The frequencies transmitted and received at the lower part of the intermediate amplifier correspond to those of the base station. Although the intermediate amplifier, which consists of the transmitter and receiver circuits of the NMT phone, causes a drop in voltage during transmission, in most cases even a low voltage is sufficient due to the limited space inside.

Because information is transmitted between the two parts of the intermediate amplifier at the audio frequency, economical wires are used. However, when using hubs, several wires can be run from the top of the intermediate amplifier, the ends of which are arranged in different compartments or spaces so that information can be transmitted to desired locations. In the simplest embodiment of the invention, only one subscriber is connected to the mobile telephone information exchange stream at an existing frequency at a time. Depending on the number of invitations, it is possible to select the system of the desired size. The invention is particularly concerned with a small information flow communication.

Any copper cable, fiber optic, radio line or, for example, a twin cable can be used as a transmission path 7 between the upper and lower parts of the intermediate amplifier. The interleaver must receive the messages and pass them along the transmission path 7. In this way, the cellular information stream may be transmitted in time, code, or frequency type signals.

The upper and lower parts of the intermediate amplifier can be made as a module to be constructed, so that, at a set frequency, the call flow can be routed through several channels.

Fig. 10 illustrates in more detail the one-way transmission of information from a base station to a mobile phone. It should be noted that information can be transmitted in the opposite direction when reverse contours are used. The information is transmitted from the base station 1, received by the receiver at the top of the intermediate amplifier, converted to audio frequency and transmitted by path 7 to the transmitter 3b at the bottom of the intermediate amplifier, where the audio frequency is modulated into radio frequency and transmitted to a mobile phone 5.

The invention is described with reference only to one embodiment. However, other variations are possible within the scope of the present invention.

Claims (8)

  1. A method of transmitting information comprising transmitting information between a base station (1) and a mobile telephone (5) via an intermediate amplifier (3), characterized in that an information amplifier (3) in the path of communication is formed by interconnected audio frequency communication (7). ), two-part (3a, 3b) demodulates the radio frequency between the base station (1) and the mobile phone (5) into an audio frequency, performs reverse audio / radio frequency conversion and forwards the information thus converted to the subscriber.
  2. 2. The method of claim 1, further comprising transmitting information by radio frequency to an intermediate amplifier (3a), which is a radio transceiver, demodulating it from radio frequency to audio frequency, transmitting demodulated information by transmission path (7) to another receiver- transmitter (3b), where it modulates the audio frequency into a radio frequency and transmits it to the mobile phone (5).
  3. 3. The method of claim 1, further comprising transmitting a frequency-type signal through the intermediate amplifier (3a, 3b).
  4. 4. The method of claim 1, further comprising transmitting a time-type signal via the intermediate amplifier (3a, 3b).
  5. 5. The method of claim 1, further comprising transmitting a code-like signal via an intermediate amplifier (3a, 3b).
  6. 6. A method according to claim 1, characterized in that the frequencies transmitted and received by the lower part (3b) of the intermediate amplifier correspond to the frequencies of the base station (1).
  7. 7. A device for transmitting information between a base station (1) and a mobile phone (5) via an intermediate amplifier (3), characterized in that an intermediate amplifier (3) is provided between the base station (1) and the mobile phone (5). parts (3a, 3b) connected by an audio frequency connection (7) for converting the radio frequency to the audio frequency and vice versa and for transmitting the converted information to the subscriber.
  8. 8. A device according to claim 8, characterized in that the audio frequency connection is a radio connection, a copper wire, a fiber optic cable or a twin wire.
LT96-078A 1995-10-30 1996-05-31 Assembly and method for transmitting information LT4204B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FI955179A FI955179A0 (en) 1995-10-30 1995-10-30 Anordning och foerfarande Foer dataoeverfoering

Publications (2)

Publication Number Publication Date
LT96078A LT96078A (en) 1997-05-26
LT4204B true LT4204B (en) 1997-08-25



Family Applications (1)

Application Number Title Priority Date Filing Date
LT96-078A LT4204B (en) 1995-10-30 1996-05-31 Assembly and method for transmitting information

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FI (1) FI955179A0 (en)
LT (1) LT4204B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4698805A (en) 1985-09-13 1987-10-06 Motorola, Inc. Console interface for a trunked radio system
US4941200A (en) 1987-08-03 1990-07-10 Orion Industries, Inc. Booster
WO1992013400A1 (en) 1991-01-15 1992-08-06 Rogers Cable T.V. Limited Radiotelephony system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4698805A (en) 1985-09-13 1987-10-06 Motorola, Inc. Console interface for a trunked radio system
US4941200A (en) 1987-08-03 1990-07-10 Orion Industries, Inc. Booster
WO1992013400A1 (en) 1991-01-15 1992-08-06 Rogers Cable T.V. Limited Radiotelephony system

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FI955179A0 (en) 1995-10-30
LT96078A (en) 1997-05-26
FI955179D0 (en)

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