WO2009008661A1

WO2009008661A1 - Mobile communication repeating system for elevator

Info

Publication number: WO2009008661A1
Application number: PCT/KR2008/004028
Authority: WO
Inventors: Seung Ha Yoo; Byeong Ho Ahn
Original assignee: A & P Technology Co.
Priority date: 2007-07-11
Filing date: 2008-07-09
Publication date: 2009-01-15
Also published as: KR20090006706A

Abstract

A mobile communication repeating system for an elevator is provided for improving communication quality in the elevator so as to secure the security of passengers safety and the elevator itself. The mobile communication repeating system of the present invention improves service quality of a mobile communication system in an elevator cage so as to secure passengers' security even in an emergency condition. Also, the mobile communication repeating system of the present invention provides signal repeating service with minimized electromagnetic radiation, resulting in protection of passengers health. Also, the mobile communication repeating system of the preset invention enables a mobile phone operates normally in the elevator cage, thereby securing passengers' security in an emergency condition.

Description

MOBILE COMMUNICATION REPEATING SYSTEM FOR

ELEVATOR

Technical Field

[1] The present invention relates to a mobile communication repeating system installed in an elevator and, in particular, to a mobile communication repeating system for an elevator that is capable of improving communication service quality in the elevator, resulting in securing the security of passengers safety and the elevator itself.

[2]

Background Art

[3] With the increase of social and economic involvement of individuals and development of information technologies, mobile communication is becoming as an essential communication mode and a dominant part of business interaction due to its spatial and temporal restriction free communication advantages.

[4] A mobile phone, as a representative wireless communication device, enables a user to communicate with the others anywhere anytime. However, the mobile phone is configured to operate in specific receiving and transmission power ranges such that communication fails out of these ranges.

[5] Typically, a mobile phone is designed such that the sum of the receiving and transmission power levels becomes -76dBm. In more detail, the receiving power level is determined in the range between -6IdBm and -10OdBm, and the transmission power level is determined in the range between -15dBm and 24dBm. Accordingly, when the receiving power level is around -99 ~ -10OdBm, the transmission power level of the mobile phone becomes maximum around 23 ~ 24dBm, such that if the transmission power is lowered below the maximum transmission power level, reliable communication is impossible. In the meantime, the mobile phone maintains a control channel with a base station even when it operates in the idle mode, and transmits signals at maximum transmission power level in an area where the receiving power is weak.

[6] In the idle mode, the mobile phone continues transmission, and the transmission power level increases as the receiving power level decreases. This means that the transmission power level increases when the communication conditions are bad and, in turn, increases the electromagnetic wave pollution.

[7] With the increase of the use of electric appliances such as microwave oven, industrial high frequency equipments, and medical apparatus, various researches have been done for proving the bad effects of the electromagnetic wave to the human body. As the results, it is found that the exposure to strong electromagnetic wave influences the bio- activity of the body so as to increase cardiac temperature and neurotic and muscular tensions. For this reason, many countries have prepared safety standards for restricting electromagnetic radiation. However, these standards differ from each other in criteria from country to country and are used as recommendations only without legal effects.

[8] In the case of mobile phone, although the transmission power level is -9dBm when the receiving power level is -67dBm, it increases abruptly to 2IdBm if the receiving power level decreases to -97dBm as shown in table 1. In this case, the displacement of the transmission power level is 3OdBm. This means the transmission power increases 1,000 times in percentage basis, resulting in proportional increase of the electromagnetic wave pollution.

[9] Table 1 [Table 1] [Table ]

[10] Referring to table 1, if the receiving power is maintained in high level, it is possible to reduce the transmission power and, in turn, the electromagnetic radiation. [H] However, in a closed space, particularly inside an elevator cage surrounded by metallic walls, the receiving power level is lowered significantly such that the mobile phone users experience that the communication cuts off frequently. That is, the transmission power of the mobile phone is likely to become maximal due to the low receiving power level in the elevator cage. The excessive electromagnetic radiation in the elevator may disturb the control mechanism of the elevator to threat the security of the elevator.

[12] In order to solve these problems, various methods for improving the communication quality of the mobile phone in the closed place such as elevator.

[13] One approach is to install a mobile communication radio antenna on the ceiling of a corridor in front of the entrance of the elevator such that the signals permeate into the elevator cage. However, this method has a drawback in that the receiving power falls down when the door of the elevator is closed. The displacement of the receiving power level between close and open states of the elevator door is about 30 ~ 4OdBm. In order to compensate the deterioration of the receiving power level, it can be considered to increase the transmission power of the mobile communication radio antenna on the ceiling and install the mobile communication radio antenna on every floor. However, such increases antenna s transmission power and the number of antennas address other problems such as increase of installment and maintenance costs and electromagnetic radiation due to the increased transmission power and number of the fixed antennas.

[14] Second, it can be considered to install the mobile communication antennas on the ceiling and bottom floor of the hoistway or on the side wall in the middle of the hoistway. In this method, however, since the elevator cage is isolated by means of hexagonal metal plates, it is difficult to expect significant positive effects. Even though there is a little effect, the receiving power level inside the elevator cage may fluctuate as the elevator moves in irregular speed, resulting in degradation of service quality.

[15] In the mean time, most elevator systems are provided with an interphone installed inside each elevator cage such that, when the elevator stops working, the passengers can communicate with an operator or a maintenance company. Unfortunately, if the interphone is not working too, the passenger is likely to try contact anybody outside the elevator cage using his/her mobile phone. Accordingly, it is significantly required to secure the communication reliability of the mobile phone in an emergency state, e.g. in the broken elevator.

[16] For these reasons, there has been a need for developing mobile communication repeating system for an elevator that is capable of securing reliable service quality of the mobile phone even in a closed space without disturbing operation of the elevator system while maintaining low electromagnetic radiation level. Disclosure of Invention Technical Problem

[17] The present invention has been made in an effort to solve the above problems, and the present invention provides a mobile communication repeating system that is capable of providing a mobile phone with stable communication service in an elevator cage, thereby securing passengers security even in an emergency condition.

[18] Also, the present invention provides a mobile communication repeating system for an elevator that is capable of minimizing electromagnetic radiation so as to prevent the operation of the elevator from being disturbed by excessive electromagnetic radiation, resulting in improvement of elevator security. Technical Solution

[19] In accordance with an exemplary embodiment of the present invention, a mobile communication repeating system for an elevator includes a signal relay unit connecting at least one repeater to a closed-circuit television (CCTV) line for relaying a mobile communication signal through the CCTV; a diplexer connected to one end of the CCTV line for splitting the mobile communication signal and CCTV signal flowing on the CCTV line; and at least one antenna mounted in at least one elevator cage for radiating the mobile communication signal inside the at least one elevator cage.

[20] Preferably, the signal relay unit includes a multiplexer for multiplexing the mobile communication signals output by the at least one repeater and outputting a multiplexed signal; and a divider for dividing the multiplexed signal output by the multiplexer into multiple equiphase signals and outputting the equiphase signals to the at least elevator cage through the CCTV line.

[21] Preferably, the diplexer is a hybrid diplexer for matching an impedance of the mobile communication signal, which is 50 , to an impedance of 75 of the CCTV signal.

[22] Preferably, the at least one antenna is mounted at a position in a predetermined distance from a wall having a cage door and operating panel inside the at least one elevator cage.

[23] Preferably, the at least one antenna is configured to operate in a transmission power range of -2OdBm ~ -3OdBm.

Advantageous Effects

[24] The mobile communication repeating system of the present invention improves service quality of a mobile communication system in an elevator cage so as to secure passengers security even in an emergency condition. Also, the mobile communication repeating system of the present invention provides signal repeating service with minimized electromagnetic radiation, resulting in protection of passengers health. Also, the mobile communication repeating system of the preset invention enables a mobile phone operates normally in the elevator cage, thereby securing passengers security in an emergency condition. Brief Description of the Drawings

[25] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which: [26] FIG. Ia is a perspective view illustrating a typical elevator, and FIG. Ib is a side elevation view illustrating the elevator of FIG. Ia; [27] FIG. 2 is a schematic diagram illustrating a mobile communication repeating system adopted to an elevator according to an exemplary embodiment of the present invention; [28] FIG. 3 is a top plan view illustrating an elevator cage of an elevator equipped with a mobile communication repeating system according to an exemplary embodiment of the present invention; [29] FIG. 4 is a photograph illustrating a microwave measurement process to a fluorescent lamp; [30] FIG. 5 is a photograph illustrating a magnetic field measurement process to the fluorescent lamp; [31] FIG. 6 is a photograph illustrating an electric field measurement process to the fluorescent lamp; [32] FIG. 7 is a photograph illustrating a magnetic field measurement process to a body of a new model laptop computer; [33] FIG. 8 is a photograph illustrating a magnetic field measurement process to a display of the laptop computer of FIG. 7; [34] FIG. 9 is a photograph illustrating a magnetic field measurement process to a display of an old model laptop computer; [35] FIG. 10 is a photograph illustrating a magnetic field measurement process in a close distance from an operating panel of an elevator cage; [36] FIG. 11 is a photograph illustrating a magnetic field measure process in a distance of

30cm from the operating panel of FIG. 10; [37] FIG. 12 is a photograph illustrating a magnetic field measurement process right below a CRT monitor; [38] FIG. 13 is a photograph illustrating a magnetic field measurement process in a distance of 30cm from the CRT monitor; [39] FIG. 14 is a photograph illustrating a magnetic field measurement process to a mobile phone with a receiving power level of -95 dBm; [40] FIG. 15 is a photograph illustrating a microwave measurement process to the mobile phone of FIG. 14 with a receiving power level of -94 dBm; [41] FIG. 16 is a photograph illustrating a microwave measurement process to the mobile phone of FIG. 14 with a receiving power set to -65 dBm;

[42] FIG. 17 is a photograph illustrating a magnetic field measurement process to a mobile phone when the receiving power of the mobile phone is set to -65dBm;

[43] FIG. 18 is a photograph illustrating a magnetic field measurement process to a mobile phone when the receiving power of the mobile phone is set to -73dBm;

[44] FIG. 19 is a photograph illustrating a magnetic field measurement process to a mobile phone when the receiving power of the mobile phone is set to -74dBm;

[45] FIG. 20 is a photograph illustrating a microwave measurement process to the mobile phone when the receiving power is set to -75dBm;

[46] FIG. 21 is a photograph illustrating a microwave measurement process to the mobile phone transmitting a text message when the receiving power is set to -103dBm;

[47] FIG. 22 is a photograph illustrating a magnetic field measurement process to the mobile phone transmitting a text message when the receiving power is set to -103dBm;

[48] FIG. 23 is a photograph illustrating a microwave radiation measurement process to the mobile phone when the receiving power is set to -103dBm; and

[49] FIG. 24 is a photograph illustrating a magnetic field measurement process to the mobile phone when the receiving power is set to -103dBm. Mode for the Invention

[50] Exemplary embodiments of the present invention are described with reference to the accompanying drawings in detail.

[51] The mobile communication repeating system for an elevator uses a closed-circuit television (CCTV) line connected to a camera installed inside an elevator cage for repeating mobile communication signals to and from a mobile phone carried by a passenger.

[52] FIG. Ia is a perspective view illustrating a typical elevator, and FIG. Ib is a side elevation view illustrating the elevator of FIG. Ia.

[53] Referring to FIGs. Ia and Ib, an elevator cage 10 carrying passengers is guided vertically along a guide rail 15 travels up and down in a hoistway. The elevator cage 10 is connected to one end of a tail cord 20 as a power cable and a CCTV cable arranged in parallel with the tail cord, the CCTV cable connecting the a CCTV camera installed inside the elevator cage 10 to a digital video recorder (DVR).

[54] FIG. 2 is a schematic diagram illustrating a mobile communication repeating system adopted to an elevator according to an exemplary embodiment of the present invention.

[55] Referring to FIG. 2, the mobile communication repeating system according to an exemplary embodiment of the present invention includes a plurality of outdoor antennas 101 that are responsible for transmitting and receiving signals to and from respective mobile communication systems, a plurality of repeaters 105 for repeating the signals, a multiplexer 110 for multiplexing the signals, a divider 115 for dividing the multiplexed signals, a hybrid diplexer 120 for combining and splitting the signals, and a plurality of indoor antennas 125 for transmitting and receiving signals to and from a mobile phone inside the elevator cage 10.

[56] Typically, the repeater 105 is installed in or around a building together with an outdoor antenna 101 for amplifying and normalizing radio signals (mobile communication signals exchanged between a mobile phone and a base station). The repeaters 105 are provided by mobile network operators for improving their communication service qualities. The mobile network operators are allocated different frequency bands such that the repeaters 105 process the radio signals on their given frequency bands. For example, the mobile network operators may provide mobile communication services on the basis of different mobile communication technologies such as Wideband Code Division Multiple Access (WCDMA), Personal Communications Service (PCS), and Wireless Broadband (WiBro) operating on different frequency bands.

[57] The multiplexer 110 performs multiplexing input signals and output the multiplexed signals into a single line.

[58] The multiplexer 100 is arranged between the repeaters and the divider 115 so as to multiplex the signals input by the repeaters 150 and outputs the multiplexed signals to the divider 115 through a signal line.

[59] The multiplexer 110 also demultiplexes mobile communication signals input by the divider 115 and outputs the signals to the corresponding repeaters 105 such that the signals are transmit over the air through corresponding frequency band antennas 101.

[60] The divider 115 divides the multiplexed signal input by the multiplexer into a plurality of equiphase signals and outputs the signals to the hybrid diplexer 120. The divider 115 also combines the signals input by the hybrid diplexer 120 and outputs the combined signal to the multiplexer 110.

[61] The hybrid diplexer 120 splits or combines the mobile communication signal and the

CCTV signal and adjusts the impedance of the mobile communication signal so as to match the impedance of the CCTV signal such that the mobile communication signal is delivered to the elevator cages 10 through the CCTV lines 50.

[62] That is, the hybrid diplexer 120 receives the CCTV signal from a DVR 40 and receives mobile communication signals via the repeaters 105, multiplexer 110, and the divider 115 and transmits the CCTV signal and the mobile communication signals to the elevator cages 10 through the CCTV lines 50 without interferences to each other.

[63] The hybrid diplexer 120 also can split the mobile communication signals input through the indoor antennas 125 of the elevator cages 10 and the CCTV signals input through CCTV cameras installed cages 10 and outputs the mobile communication signals to the divider 115 and the CCTV signals to the DVR 40.

[64] The hybrid diplexer 120 performs impedance matching so as to convert the impedance (50Ω) of the mobile communication signals to the impedance (75Ω) of the CCTV signal, thereby preventing loss of the mobile communication signals.

[65] The hybrid diplexer 120 can be arranged near the indoor antenna 125 installed inside the elevator cage 10. Preferably, the indoor antenna 125 is a broadband antenna configured to receive signals on the bandwidth between 800 MHz and 2400 MHz for covering various mobile communication services provided by different mobile communication operators.

[66] The indoor antenna 125 is configured such that its throughput is in the range of -20 ~

-30 dBm/FA(channel). With this configuration of the indoor antenna 125, the transmission power level of the mobile phone in the elevator cage 10 is about -6 — 16 dBm. Accordingly, when assuming the number of channels provided by the multiple mobile communication operators is 40, the total transmission power level of the indoor antenna 125 is about -4 ~ -14 dBm. That is, the transmission power level of the indoor antenna 12 does not exceed 0 dBm which is about 1/1000 of the transmission level of about 20 ~ 24 dBm measured when the communication fails in the conventional elevator cage, resulting in significant reduction of the electromagnetic radiation.

[67] The indoor antenna 125 is connected to one end of the CCTV line 50 arranged along the tail cord 20 in the hoistway. In order to protect circuit shortage risk, it is preferred that the CCTV line 50 is implemented with a 7 core RF-twisted cable among RG-11, RG-9, RG-59, etc. rather than 5C-HFBT (RF-75Ω Highly foamed triple dielectric signal core cable). The RG-59/58 cables are not appropriate for the mobile communication signal line since their signal attenuation exceeds 1OdB/ 10m over 2GHz frequency band. In the meantime, the RG- 11 cable shows attenuation characteristic below 3dB/10m over the 2GHz frequency band. Accordingly, it is preferred to use the RG-11 or RG-9 twisted cable having stable characteristics.

[68] The indoor antenna 125 is installed at a position in the elevator cage 10, and the installation position is determined in consideration of a few criteria. First, the installation position should be located maintaining a distance enough for minimizing interferences with the facilities such as operating panel mounted in the elevator cage 10 and minimizing the influence of the electromagnetic radiation to the passengers. Also, the indoor antenna 125 should be mounted at an area at which the indoor antenna 125 is exposed inside the cage and operates while minimizing its external damage.

[69] In view of these criteria, it is preferred that the indoor antenna 125 is installed on the ceiling and facing the door and operating panel of the elevator cage 10 as shown in FIG. 3.

[70] The operations of the above- structured mobile communication repeating system is described in more detail.

[71] In a case that the mobile communication repeating system processes incoming signals in view of the elevator cage 10, the mobile communication signals received through the outdoor antennas 101 are delivered to the multiplexer 110 via the repeaters 105 so as to be multiplexed and output to the divider 115 through the single signal line in the form of a multiplexed signal. The divider 115 divides the multiplexed signal input by the multiplexer 110 into a plurality of equiphase signals and outputs the equiphase signals to the hybrid diplexer 120. The hybrid diplexer 120 combines the equiphase signals and the CCTV signal input by the DVR 40 and sends the combined signal to the indoor antennas 125 of the respective elevator cages 10 such that the mobile phone of the passenger can selectively receive the mobile communication signal destined to itself in the elevator cage 10.

[72] In a case that the mobile communication repeating system processes outgoing signals in view of the elevator cage 10, the mobile communication signals transmitted by the mobile phones are received through the indoor antenna 125 in the elevator cage 10 and delivered to the hybrid diplexer 120 through the CCTV line 50. At this time, the CCTV signals transmitted by the CCTV cameras mounted in the respective elevator cages 10 are also delivered to the hybrid diplexer 120 through the same CCTV lines 50.

[73] The hybrid diplexer 120 splits the mobile communication signals received through the indoor antennas 125 and the CCTV signals received from the CCTV cameras such that the mobile communication signals are delivered to the divider 115 and the CCTV signals are delivered to the DVR 40. The divider 115 outputs the mobile communication signals to the multiplexer 110 through the signal line in series and the multiplexer 110 performs demultiplexing on the mobile communications according to the mobile communication operators and outputs the demultiplexed mobile communication signals to the corresponding repeaters 105 such that the mobile communication signals are transmitted through the respective outdoor antennas 101.

[74] Now the variation of the electromagnetic radiation amount before and after adopting the mobile communication repeating system of the present invention to an elevator is described. The electromagnetic ration is measured under the following conditions.

[75] In order to measure the electromagnetic radiation of electric devices mounted in the elevator cage and mobile phone, an electromagnetic wave meter which can measure the electric field, magnetic field, and microwave has been used. The electric field has been measured in the range of 0 ~ 100 kV/m, magnetic field in the ranges of 0 ~ 3 mG and 0 ~ 10OmG, and the microwave in the range of 0.01 ~ 1 mW/cm², with the frequency weights of 30 ~ 500 Hz for electric field and magnetic field and 50 MHz ~ 3 GHz for microwave.

[76] The measurement distances were differently specified for the electric devices mounted in the elevator cage from each other, and as 10cm for mobile phones. In this simulation, the measurement distance was set to 3cm for obtaining more accurate measurement results. In order to avoid interferences from other devices, the measurement has been performed in an electric wave shielding room in both states in which the door is closed and opened slightly.

[77] FIG. 4 is a photograph illustrating a microwave measurement process to a fluorescent lamp, FIG. 5 is a photograph illustrating a magnetic field measurement process to the fluorescent lamp, and FIG. 6 is a photograph illustrating an electric field measurement process to the fluorescent lamp.

[78] As shown in the photographs, the microwave radiation was 0.2 ~ 0.3 mW/cm², the magnetic field was lOOmG/m, and the electric field was 100kV/m.

[79] FIG. 7 is a photograph illustrating a magnetic field measurement process to a body of a new model laptop computer, FIG. 8 is a photograph illustrating a magnetic field measurement process to a display of the laptop computer of FIG. 7, and FIG. 9 is a photograph illustrating a magnetic field measurement process to a display of an old model laptop computer.

[80] Referring to FIGs. 7 to 9, the magnetic field was 7mG/m right above the body of the new model laptop computer and 0.5mG/m right above the display of the new model laptop computer. In the meantime, the magnetic field was 20mG/m right above the display of the old model laptop computer.

[81] FIG. 10 is a photograph illustrating a magnetic field measurement process in a close distance from an operating panel of an elevator cage, and FIG. 11 is a photograph illustrating a magnetic field measure process in a distance of 30cm from the operating panel of FIG. 10.

[82] As shown in FIGs. 10 and 11, the magnetic field was lOOmG/m near the operating panel and 20mG/m in the distance of 30cm from the operating panel.

[83] FIG. 12 is a photograph illustrating a magnetic field measurement process right below a CRT monitor, and FIG. 13 is a photograph illustrating a magnetic field measurement process in a distance of 30cm from the CRT monitor. As shown in FIGs. 12 and 13, the magnetic field was 50 mG/m right below the CRT monitor and 8 mG/m in the distance of 30cm from the CRT monitor.

[84] FIG. 14 is a photograph illustrating a magnetic field measurement process to a mobile phone with a receiving power level of -95 dBm, FIG. 15 is a photograph illustrating a microwave measurement process to the mobile phone of FIG. 14 with a receiving power level of -94 dBm, and FIG. 16 is a photograph illustrating a microwave measurement process to the mobile phone of FIG. 14 with a receiving power level of -65 dBm.

[85] In the case that the receiving power level was -95 dBm, the mobile phone failed com- munication, and the magnetic field was 35 niG/m. In the cases of the receiving power levels of -94dBm with very unstable communication and -65dBm with good communication, the microwave measurements were over lmW/cm² and below 0.01mW/cm². This means that the microwave radiation amount varies as much as 100 times according to the variation of the communication environment. In comparison with the microwave radiation amount measured without adopting the mobile communication repeating system of the present invention, which shows variations of 1000 times according to the displacement of transmission power level of 3OdBm between the receiving power levels of -67dBm and -97dBm, the electric field radiation was decreased significantly.

[86] FIGs. 17 to 19 are photographs illustrating magnetic field measurement processes to a mobile phone when the receiving power of the mobile phone is set -65dBm, -73dBm, and -74dBm, and FIG. 20 is a photograph illustrating a microwave measurement process to the mobile phone when the receiving power is set to -75dBm.

[87] When the receiving power level -65dBm, -73dBm, and -74dBm, the magnetic field measurements were 0.8mG/m, lmG/m, and 1.2mG/m, respectively. This shows that the magnetic field increases as the communication condition is deteriorated. When the receiving power level was -75dBm, the microwave radiation measurement was 0.01mW/cm² similar to the value when measured with the receiving power level of - 65mBm. This means that the microwave radiation does not increase sensitively to the decrease of the receiving power level.

[88] FIGs. 21 and 22 are photographs illustrating microwave and magnetic field measurement processes to the mobile phone transmitting a text message when the receiving power level is set to -103dBm, and FIGs. 23 and 24 are photographs illustrating microwave and magnetic field measurement processes to the mobile phone when the receiving power level is set to -103dBm.

[89] When transmitting the text message with very low receiving power level, i.e. -

103dBm, the microwave measurement was 0.2mW/cm², and the magnetic field measurement was lOmG/m.

[90] When performing voice communication with the same receiving power level, the microwave measurement was 0.2mW/cm², and the magnetic field was 25mG/m.

[91] Unlike the conventional mobile communication repeater, the mobile communication repeating system of the present invention enables the mobile phone to use communication services such as voice communication and text messaging services and reduces microwave radiation and magnetic field inside a closed elevator cage. The magnetic field and microwave radiation values measured in the elevator equipped with the mobile communication repeating system of the present invention is relatively low in comparison with the values measured for the fluorescent lamp, laptop computer, operating panel of the elevator cage 60, and CRT monitor.

[92] Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the present art will still fall within the spirit and scope of the present invention, as defined in the appended claims.

Claims

[1] A mobile communication repeating system for an elevator, comprising: a signal relay unit connecting at least one repeater to a closed-circuit television (CCTV) line for relaying a mobile communication signal through the CCTV line; a diplexer connected to one end of the CCTV line for splitting the mobile communication signal and CCTV signal flowing on the CCTV line; and at least one antenna mounted in at least one elevator cage for radiating the mobile communication signal inside the at least one elevator cage.

[2] The mobile communication repeating system of claim 1, wherein the signal relay unit comprises: a multiplexer for multiplexing the mobile communication signals output by the at least one repeater and outputting a multiplexed signal; and a divider for dividing the multiplexed signal output by the multiplexer into multiple equiphase signals and outputting the equiphase signals to the at least elevator cage through the CCTV line.

[3] The mobile communication repeating system of claim 1, wherein the diplexer is a hybrid diplexer for matching an impedance of the mobile communication signal, which is 50 , to an impedance of 75 of the CCTV signal.

[4] The mobile communication repeating system of claim 1, wherein the at least one antenna is mounted at a position in a predetermined distance from a wall having a cage door and operating panel inside the at least one elevator cage.

[5] The mobile communication repeating system of claim 1, wherein the at least one antenna is configured to operate in a transmission power range of -2OdBm ~ - 3OdBm.