AU2020202803B2

AU2020202803B2 - Coaxial cable assembly

Info

Publication number: AU2020202803B2
Application number: AU2020202803A
Authority: AU
Inventors: Jong Won Baek; Sung Su Jin
Original assignee: LS Cable and Systems Ltd
Current assignee: LS Cable and Systems Ltd
Priority date: 2019-07-10
Filing date: 2020-04-28
Publication date: 2021-11-25
Anticipated expiration: 2040-04-28
Also published as: CN112217036B; AU2020202803A1; KR102758197B1; CN112217036A; KR20210007116A

Abstract

The present invention relates to a coaxial cable assembly capable of minimizing damage to a coaxial cable due to birds and the like and improving watertightness and workability of connection work at a base station when installed outdoors. 37 Fig. 5 20 -21 31 -33 -35 37 t½39

Description

Fig. 5

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Australian Patents Act 1990

ORIGINAL COMPLETE SPECIFICATION STANDARDPATENT

Invention Title Coaxial cable assembly

The following statement is a full description of this invention, including the best method of performing it known to me/us:

TECHNICAL FIELD

[01] The present disclosure relates to a coaxial cable

assembly. More specifically, the present disclosure relates to a

coaxial cable assembly capable of minimizing damage to a coaxial

cable due to birds and the like and improving watertightness and

workability of connection work at a base station when installed

outdoors.

BACKGROUND

[01A] Conventionally, for mobile communication, a

communication signal is transmitted from a key communication

station or the like to a base station and a radio-frequency (RF)

signal transmitted from a base transceiver station (BTS) of the

base station is transmitted wirelessly via an antenna of the base

station. A radio signal transmitted from a user's portable

terminal is received via the antenna of the base station, amplified

by a tower mounted amplifier (TMA), and transmitted to the BTS.

[02] In this case, the BTS, the TMA, and the antenna of

the base station are connected to one another via a coaxial feeder

la but signal loss in the coaxial feeder increases as the length of a cable is increased. When the antenna is installed at a tower having a height of several tens of meters, signal loss in the coaxial feeder connecting the base station on the ground and the antenna increases. Thus, a signal transmitted from the base station does not reach signal intensity required at the antenna and attenuates due to the signal loss in the coaxial feeder.

Accordingly, the TMA is installed to compensate for the attenuation

of the signal and amplify the signal.

[03] However, a relatively large amount of power is

consumed by the TMA to amplify the signal and thus maintenance

costs of the whole system are high. Accordingly, the efficiency

of the TMA is low.

[04] With the advancement of FTTx (Fiber to the X) and a

decrease in the size of a repeater, base station equipment has been

developed. A signal attenuation rate in an optical unit according

to a cable length among the base station equipment is very lower

than that in a coaxial cable. Remote radio head (RRH) which is

technology employing the above-described advantage of the optical

unit has been introduced, whereby an optical signal is transmitted

right before an antenna of a based station to minimize signal loss and is converted into an RF signal, which can be emitted, right before the antenna.

[05] RRH may make up for disadvantages of a mobile

communication base station using the TMA, e.g., high power

consumption and an inefficient maintenance method. In RRH, a

remote RF unit (RRU) is separated from a BTS, arranged below an

antenna of a tower of a base station, and remotely controlled.

[06] Here, in RRH, remaining part, i.e., a baseband unit

(BBU) and a power supply unit (PSU), of the BTS from which the RRU

is separated are connected to the RRU via an optical fiber and

power line composite cable having an optical unit in which signal

attenuation hardly occurs according to a cable length and a power

unit. Accordingly, a communication signal is supplied to the RRU

from the BBU via the optical unit of the optical fiber and power

line composite cable, and power is supplied to the RRU from the

PSU via the power unit of the optical fiber and power line composite

cable.

[07] Since the RRU may be installed right below the

antenna of the base station at the top of the tower of the base

station, a length of a coaxial feeder supplying a signal converted

into an RF signal by the RRU to the antenna may be minimized and thus attenuation of the RF signal when transmitted via a coaxial line may not be a serious problem. Accordingly, a degree of attenuation of the signal right before the signal is emitted may be minimized and thus the TMA which consumes a large amount of power is not needed. The technical features of the RRH are advantageous in terms of maintenance of the base station.

[08] In such an RRH system, the BBU, the PSU, and the

RRU are connected to one another via a terminal box for an optical

fiber and power line composite cable.

[09] That is, in the optical fiber and power line

composite cable connected to the base station, a plurality of

optical units and a plurality of power units are provided in the

form of a cable. Accordingly, the BBU, the PSU, and a plurality

of RRUs cannot be directly connected to the optical fiber and power

line composite cable and thus the RRUs and terminal boxes for the

optical fiber and power line composite cable may be connected using

a separate jumper cable.

[10] In these remote radio head (RRH) base station

systems, an antenna of a base station is mounted to be projected

out on the top of a tower of the base station, and a coaxial cable

connecting the antenna on the top of the tower and a remote radio unit (RRU) is likely to be exposed to birds and damaged by birds' beaks. In order to connect the antenna and the RRU, the coaxial cable is connected to the antenna and the RRU through a connector and thus moisture may permeate the antenna, the RRU, or the coaxial cable through a connector connection portion in case of rain.

[11] As described above, when a failure or corrosion

occurs due to physical damage to or moisture permeating the coaxial

cable connecting the antenna on the top of the tower of the base

station and the RRU, a worker should approach the top of the tower

to perform work and thus workability is low and costs and risk for

maintenance and repair increase.

[11A] It is desired to address or ameliorate one or more

disadvantages or limitations associated with the prior art, or to

at least provide a useful alternative.

SUMMARY

[11B] According to the present invention there is provided

a coaxial cable assembly comprising:

a coaxial cable;

coaxial connectors connected to both ends of the coaxial

cable; a cable protection tube surrounding an outside of the coaxial cable to expose a predetermined end region of the coaxial cable so as to prevent damage to the coaxial cable; a sealing member configured to seal an interface between the coaxial connector and a corresponding connector coupled with the coaxial connector, the sealing member being provided in an elastic pipe form; and a protective cap configured to accommodate and close the sealing member in a direction toward the corresponding connector after the sealing member is mounted thereon, wherein the protective cap is fixed by the sealing member, wherein the sealing member comprises a plurality of protruding ribs configured to prevent the sealing member from slipping, and wherein the protective cap comprises at least one locking groove configured to catch at least one protruding rib of the sealing member and the at least one locking groove being provided in an inner circumferential surface of the protective cap.

[11C] According to the present invention there is further

provided a remote radio head (RRH) base station system comprising:

a terminal box configured to split at least one optical fiber

and power line composite cable connected thereto, wherein the at least one optical fiber and power line composite cable comprises a plurality of power units and a plurality of optical units for supplying power and data from a power supply unit (PSU) and a baseband processing unit (BBU) on the earth; a remote radio unit (RRU) connected to the terminal box, at least one power unit, and a jumper cable including at least one unit; an antenna configured to transmit a radio-frequency (RF) signal to and receive an RF signal from the RRU; and the above coaxial cable assembly, the coaxial cable assembly being configured to connect the RRU and the antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

[11D] Some embodiments of the present invention are

hereinafter described, by way of non-limiting example only, with

reference to the accompanying drawings, in which:

[11E] FIG. 1 illustrates a structure of a base station at

which a coaxial cable assembly according to an embodiment of the

present disclosure is installed;

[11F] FIG. 2 is a cross-sectional view of an optical fiber

and power line composite cable introduced and split or connected in a terminal box for an optical fiber and power line composite cable, according to the present disclosure;

[11G] FIG. 3 is a close-up perspective view of a

connection state of an coaxial cable assembly connecting an antenna

and a remote radio unit (RRU) of a remote radio head (RRH) system,

according to the present disclosure;

[11H] FIG. 4 illustrates a coaxial cable assembly

according to the disclosure;

[11I] FIGS. 5 through 8 illustrate a process of connecting

a coaxial cable assembly to an antenna, according to the present

disclosure;

[11J] FIGS. 9 and 10 are a side view and a cross-sectional

view of a sealing member of a coaxial cable assembly according to

the present disclosure; and

[11K] FIG. 11 is a cross-sectional view of a state in

which a sealing member and a cap member of a coaxial cable assembly

according to the present disclosure are mounted.

DETAILED DESCRIPTION

[12] The present disclosure relates to a coaxial cable

assembly capable of minimizing damage to a coaxial cable due to birds and improving watertightness and workability of connection work at a base station when installed outdoors.

[13] To achieve these objects, the present disclosure

provides a coaxial cable assembly comprising: a coaxial cable;

coaxial connectors connected to both ends of the coaxial cable; a

cable protection tube surrounding an outside of the coaxial cable

to expose a predetermined end region of the coaxial cable so as to

prevent damage to the coaxial cable; a sealing member configured

to seal an interface between the coaxial connector and a

corresponding connector coupled with the coaxial connector, the

sealing member being provided in an elastic pipe form; and a

protective cap configured to accommodate and close the sealing

member in a direction toward the corresponding connector after the

sealing member is mounted thereon.

[14] And the coaxial cable may further comprise a heat

shrinkable tube configured to surround and close connection

portions of the coaxial connectors connected to both ends of the

coaxial cable, starting from both end regions of the cable

protection tube.

[15] And the sealing member may comprise an entrance and

an exit at both ends thereof, wherein inner diameters of the entrance and the exit are less than an outer diameter of the coaxial cable on which the heat shrinkable tube is mounted.

[16] And the coaxial cable may further comprise a tube

expansion part provided between the entrance and the exit of the

sealing member to accommodate the interface between the coaxial

connector and the corresponding connector, the tube expansion part

having an enlarged inner diameter.

[17] And the tube expansion part of the sealing member

may be provided closer to the exit facing the coaxial connector

than the entrance.

[18] [Blank]

[19] And the inner diameter of the exit of the sealing

member may be larger than that of the entrance of the sealing

member.

[20] And the coaxial cable may further comprise a

plurality of protruding ribs configured to prevent the sealing

member from slipping, the plurality of protruding ribs being

provided on a region of the sealing member other than the tube

expansion part in a circumferential direction.

[21] And the coaxial cable may further comprise at least

one locking groove configured to catch at least one protruding rib of the sealing member, the at least one locking groove being provided in an inner circumferential surface of the protective cap.

[22] And the sealing member may comprise a plurality of

ring-shaped protruding ribs, wherein a protruding rib adjacent to

the entrance among the plurality of protruding ribs is placed in

the locking groove when the protective cap is mounted surrounding

the sealing member.

[23] And the sealing member may be maintained in a shrunk

state when an outer circumferential surface thereof is pressed to

remove an inner empty space of the sealing member while the sealing

member is mounted.

[24] And the coaxial cable assembly may be configured to

connect a remote radio unit (RRU) and an antenna in a remote radio

head (RRH) base station system.

[25] [Blank]

[26] And to achieve these objects, the present disclosure

provides a remote radio head (RRH) base station system comprising:

a terminal box configured to split at least one optical fiber and

power line composite cable connected thereto, wherein the at least

one optical fiber and power line composite cable comprises a

plurality of power units and a plurality of optical units for

supplying power and data from a power supply unit (PSU) and a baseband processing unit (BBU) on the earth; a remote radio unit

(RRU) connected to the terminal box, at least one power unit, and

a jumper cable including at least one unit; an antenna configured

to transmit a radio-frequency (RF) signal to and receive an RF

signal from the RRU; and the coaxial cable assembly discussed above,

the coaxial cable assembly being configured to connect the RRU and

the antenna.

[27] [Blank]

[28] [Blank]

[29] [Blank]

[30] [Blank]

[31] [Blank]

[32] [Blank]

[33] [Blank]

[34] Hereinafter, exemplary embodiments of the present

disclosure will be described in detail with reference to the

accompanying drawings. The present invention, however, need not

be limited thereto and may be embodied in many different forms.

Rather, the embodiments set forth herein are provided so that this

disclosure may be thorough and complete and fully convey the scope

of the invention to those skilled in the art. Throughout the specification, the same reference numbers represent the same elements.

[35] FIG. 1 illustrates a structure of a base station at

which a coaxial cable assembly according to an embodiment of the

present disclosure is installed.

[36] Referring to FIG. 1, in a remote radio head (RRH)

base station system 1, a remote radio unit (RRU) 40 is separated

from an existing base station and disposed below an antenna 20 at

a base station tower, and remotely controlled.

[37] Here, in the RRH base station system 1, a remaining

part 10 of the BTS from which the RRU 40 is separated, i.e., a

baseband processing unit (BBU) and a power supply unit (PSU), and

the RRU 40 are connected to an optical fiber and power line

composite cable 100 which includes an optical unit 130 in which

attenuation hardly occurs per length and a power unit 110.

[38] Communication signals from the BBU and the PSU are

supplied to the RRU 40 via the optical unit 130 of the optical

fiber and power line composite cable 100, and power is supplied to

the RRU 40 via the power unit 110 of the optical fiber and power

line composite cable 100.

[39] Because the RRU 40 may be installed directly below

the antenna 20 on the top of the base station tower, the coaxial cable assembly 30 according to the present disclosure for supplying to the antenna 20 an RF signal obtained through conversion by the

RRU 40 may be minimized in length and thus attenuation of the RF

signal that may occur when the RF signal is transmitted via the

coaxial cable assembly 30 according to the present disclosure may

not be a problem. Thus, attenuation of a signal immediately before

emission thereof may be minimized and a tower-mounted amplifier

(TMA) consuming a large amount of power is not required. Such

technical features are strong points of an RRH in terms of

maintenance of a base station.

[40] As described above, when a failure or corrosion

occurs in the RRH base station system due to physical damage to or

moisture permeating the coaxial cable connecting the antenna on

the top of the base station tower and the RRU, a worker should

approach the top of the base station tower to perform work and thus

workability is low and costs and risk of maintenance may increase.

[41] Therefore, in the RRH base station system according

to the present disclosure, the coaxial cable assembly 30 of a new

structure is employed as a connection means for connection of a

base station antenna and an RRU instead of a general coaxial cable,

thereby minimizing damage due to birds and the permeation of

moisture. A structure of the coaxial cable assembly 30 according to the present disclosure will be described in detail with reference to FIG. 3 below.

[42] In the RRH base station system 1, the part 10

consisting of the BBU and the PSU and the optical fiber and power

line composite cable 100 are connected via a terminal box 1200 for

an optical fiber and power line composite cable as illustrated in

FIG. 1.

[43] The optical unit 130 (see FIG. 2) of the optical

fiber and power line composite cable 100 is connected to the BBU

and the power unit 110 (see FIG. 2) is connected to the PSU.

[44] That is, the optical fiber and power line composite

cable 100 is a cable consisting of a plurality of optical units

and a plurality of power units and thus cannot be directly connected

to the part 10 consisting of the BBU and the PSU and various types

of RRUs installed at one base station tower. The optical units

and the power units may be split from the optical fiber and power

line composite cable 100 inside the terminal box 1200 for an optical

fiber and power line composite cable and connected to a plurality

of RRUs 40 via a jumper cable 50.

[45] FIG. 2 is a cross-sectional view of an optical fiber

and power line composite cable introduced and split or connected in a terminal box for an optical fiber and power line composite cable, according to the present disclosure.

[46] Referring to FIG. 2, an optical fiber and power line

composite cable 100 may include a cable core 105 and a sheath layer

150 covering the cable core 105.

[47] The cable core 105 may include a plurality of power

units 110 for supplying power and a plurality of optical units 130

for transmitting an optical signal.

[48] A central tensile wire 145 may be provided at the

center of the optical fiber and power line composite cable 100,

and the plurality of optical units 130 may be provided around the

central tensile wire 145 in a lengthwise direction of the optical

fiber and power line composite cable 100.

[49] A protective layer 140 may be further provided

outside the plurality of optical units 130 to protect the plurality

of optical units 130.

[50] The optical unit 130 may be configured in any form

including an optical fiber for transmission of an optical signal,

and may include, for example, an optical fiber 133 with at least

one core and a tube 135 surrounding the optical fiber 133. The

tube 135 may be formed of, for example, polybutylene terephthalate

(PBT), polypropylene, polyethylene, polyvinyl chloride, or the like.

In addition, the inside of the tube 135 may be filled with a filler

137 such as jelly or waterproof yarn. For example, the inside of

the tube 135 may be filled with jelly or a tensile member (not

shown) such as aramid yarn. The tensile member is excellent in

tensile strength and flexible and thus secures stable installment

of a cable.

[51] In addition, as described below, the optical unit

130 may include a plurality of optical fibers and be connected to

an Multiple-fiber Push-On (MPO) optical connector such that the

plurality of optical fibers branch from the optical unit 130 and

are connected to a plurality of jumper cables.

[52] The optical unit 130 may be configured in a desired

form among various forms such as a tight buffer type or a loose

tube type.

[53] Each of the power units 110 includes a conductor

113 and an insulator 115 covering the conductor 113. The power

units 110 may be in a form conforming to a general-power standard

and the conductors 113 may be twisted together. The conductor 113

may be formed of a metal such as copper or aluminum, and the

insulator 115 may be formed of a polymer resin such as polyethylene,

polypropylene, or polyvinyl chloride.

[54] When the optical unit 130 and the power unit 110

are compared with each other, the optical unit 130 is smaller in

diameter than the power unit 110 and the optical fiber 133 included

in the optical unit 130 is relatively vulnerable to bending or

breaking. Therefore, the optical unit 130 may be disposed in a

central region of the optical fiber and power line composite cable

100, the outside of the optical unit 130 may be covered with the

protective layer 140, and the power unit 110 may be disposed on an

outer circumferential surface of the protective layer 140.

[55] The cable core 105 may further include a filler 120

filling gaps between the plurality of power units 110 or the

plurality of optical units 130.

[56] The power units 110 each have a circular shape and

thus a void or clearance occurs between neighboring power units

110. Due to the above configuration, the exterior of the optical

fiber and power line composite cable 100 cannot be maintained in a

circular shape and thus the optical fiber and power line composite

cable 100 is vulnerable to bending or impact applied from the

outside. Therefore, voids in the cable core 105 may be filled with

the filler 120 and the exterior of the filler 120 may be maintained

in a circular shape to withstand external shocks and the like.

[57] The sheath layer 150 which is an outermost layer of

the optical fiber and power line composite cable 100 forms the

exterior of the optical fiber and power line composite cable 100

and protects the optical units 130 and the power units 110 of the

optical fiber and power line composite cable 100.

[58] The sheath layer 150 may be inscribed in the cable

core 105, and include a non-woven tape 151 covering the outer

circumference of the cable core 105, a metal protective layer 153

provided on the outside of the non-woven tape 151 to surround the

cable core 105 in a circular shape and protect the cable core 105

from external impacts, and an outer jacket 155 surrounding the

metal protective layer 153.

[59] The non-woven tape 151 is provided on the outside

of the cable core 105 to surround the outer circumference of the

cable core 105 and surround the power units 110 and the optical

units 130 in a circular shape. The non-woven tape 151 may be a

compressed non-woven fabric and be disposed to cover the optical

units 130 and the power units 110 inside the non-woven tape 151.

The non-woven tape 151 may be formed by cross-winding or vertically

adding a tape type material.

[60] The metal protective layer 153 may be corrugated

such that peaks and valleys are repeatedly formed to cover the

cable core 105.

[61] For example, the metal protective layer 153 may be

in a corrugated form with alternating peaks and valleys and be

embodied as a metal pipe formed of aluminum or the like. A method

of forming the metal protective layer 153 will now be described.

A pipe having a certain diameter is manufactured by providing a

plate type metal board together with the cable core 105 including

the optical units 130 and the power units 110, rolling the metal

board to cover the outside of the cable core 105, and bonding both

ends of the metal board, which are in contact with each other, by

welding or the like. Next, the pipe may be pressed at certain

intervals to form corrugations outside the pipe.

[62] The outer jacket 155 may be formed of a resin which

has a flame-retardant property and is eco-friendly. For example,

the outer jacket 155 may be formed of polyethylene, polypropylene,

polyvinyl chloride (PVC), or the like.

[63] The optical fiber and power line composite cable

100 is connected to the jumper cable 50 connected to the RRU 40

after being split into the power units 110 and the optical units

130 in the terminal box 1200.

[64] The structure of the coaxial cable assembly 30

according to the present disclosure will be described in detail

below.

[65] FIG. 3 is a close-up perspective view of a

connection state of the coaxial cable assembly 30 connecting the

antenna 20 and the RRU 40 of an RRH system, according to the present

disclosure. FIG. 4 illustrates the coaxial cable assembly 30

according to the disclosure.

[66] For convenience of explanation, FIG. 4 illustrates

the proximity of a connector at one side of the coaxial cable

assembly 30 to which a sealing member 35 and a protective cap 37

are pushed backward and the proximity of a connector at another

side of the coaxial cable assembly 30 at which the sealing member

35 and the protective cap 37 are assembled together.

[67] The RRH base station system may be installed at a

base station tower, the antenna 20 may be installed at the top of

the base station tower, the RRU 40 may be installed below the

antenna 20, and the antenna 20 and the RRU 40 may be connected via

the coaxial cable assembly 30 according to the present disclosure.

[68] As described above, when a coaxial cable of the

coaxial cable assembly 30 is exposed to the outside, an outer jacket of a coaxial cable and the like may be easily damaged by birds.

[69] Therefore, the coaxial cable assembly 30 according

to the present disclosure may include a cable protection tube 39

to accommodate the coaxial cable therein.

[70] The cable protection tube 39 may be formed of a

material having a certain degree of flexibility and a degree of

hardness not to be damaged by birds' beaks. The cable protection

tube 39 may be corrugated such that valleys and peaks are repeated.

[71] Because the antenna 20 of the base station and the

RRU 40 are structurally exposed to the outside and thus are

continuously exposed to snow and rain, the coaxial cable assembly

30 according to the present disclosure may include the sealing

member 35 formed of a flexible material to seal each connector

connection portion so as to prevent the permeation of moisture into

an interface between the antenna 20 and the RRU 40, and may further

include the protective cap 37 to protect and close the sealing

member 35.

[72] Thus, as illustrated in FIG. 3, the antenna 20 of

the base station and the RRU 40 form a coaxial feed line together

with the coaxial cable through connectors at an end of the coaxial

cable and at a device, but the coaxial cable and connector connection parts are not exposed to the outside to prevent damage to or moisture penetration into the coaxial cable, thereby facilitating maintenance of the antenna 20 of the base station.

[73] The coaxial cable assembly 30 according to the

present disclosure may include the coaxial cable; the coaxial

connectors 31 connected to both ends of the coaxial cable; the

cable protection tube 39 configured to cover the outside of the

coaxial cable to expose a predetermined end region of the coaxial

cable, thereby preventing damage to the coaxial cable; the sealing

member 35 which is in the form of an elastic pipe for sealing

interfaces between the coaxial connectors 31 and corresponding

connectors coupled with the coaxial connectors 31; and the

protective cap 37 for accommodating and closing the sealing member

35 in a direction toward the corresponding connectors after the

sealing member 35 is mounted thereon.

[74] The coaxial cable assembly 30 according to the

present disclosure may include the coaxial cable to transmit and

receive an RF signal between the antenna 20 and the RRU 40, and

the coaxial connectors 31 at both ends of the coaxial cable.

[75] Because standards of connection to the antenna 20

and the RRU 40 may be different, each of the coaxial connectors 31

provided at both ends of the coaxial cable of the present disclosure may be configured to conform to the CHFS 1/4" standard, the CHFS

3/8" standard, the CHFS 1/2" standard, the CHFA 3/8" standard, the

CHF 1/2" standard, or the CLH 7/8" standard.

[76] The cable protection tube 39 may be provided to

surround the outside of the coaxial cable having both ends

connected to the coaxial connectors 31 to expose a predetermined

end region of the coaxial cable assembly 30, thereby preventing

damage to the coaxial cable assembly 30. The cable protection tube

39 may have a corrugation structure to secure flexibility and

prevent bending and be formed of a material capable of preventing

damage by birds.

[77] As illustrated in FIG. 4, the cable protection tube

39 may have a length sufficient to expose both end regions of the

coaxial cable. That is, the coaxial connectors 31 may be connected

to both ends of the coaxial cable, and the cable protection tube

39 may be set to be shorter than the coaxial cable to close with

the heat shrinkable tube 33 so as to prevent the permeation of

moisture between the cable protection tube 39 and the coaxial cable.

[78] The heat shrinkable tube 33 is a closing member

formed of a resin material, the inner diameter of which shrinks

when heat is applied thereto, and has a property of shrinking while surrounding the outer circumferential surface of an object to be closed.

[79] As illustrated in FIG. 4, the heat shrinkable tube

33 may be installed and shrink in a boundary region between the

coaxial cable and the cable protection tube 39 having a length

sufficient to expose a predetermined end region of the coaxial

cable, thereby closing the cable protection tube 39 and the

boundary region and preventing the permeation of moisture into the

boundary region.

[80] The heat shrinkable tube 33 closes the boundary

region between the cable protection tube 39 and the coaxial cable

but a corresponding connector 21 of the antenna 20 or the RRU 41

and the coaxial connector 31 at an end of the coaxial cable are

connected at a base station tower. Therefore, the coaxial

connector 31 is not a closing part of the heat shrinkable tube 33.

[81] Therefore, the sealing member 35 may be further

provided to seal a connector connection portion and an end of the

heat shrinkable tube 33 near the coaxial connector 31 after

connection of connectors is completed by a worker. The sealing

member 35 may be configured as a flexible pipe.

[82] The sealing member 35 may include an entrance 357

and an exit 351 at both ends thereof and inner diameters of the entrance 357 and the exit 351 (see FIG. 9) may be set to be less than an outer diameter of the coaxial cable on which the heat shrinkable tube 33 is mounted to achieve a substantial sealing effect. Alternatively, the entrance 357 and the exit 351 may be different in inner diameter. The sealing member 35 will be described in detail below.

[83] The protective cap 37 may be provided on the outer

side of the sealing member 35. The protective cap 37 accommodates

and protects the entire sealing member 35 formed of a flexible

material and is configured to fix the sealing member 35 by mounting

the sealing member 35 on a connector connection portion and

inserting it into the protective cap 37.

[84] Therefore, the sealing member 35 and the protective

cap 37 may be fixed by press-fitting the sealing member 35 into

the protective cap 37 without a separate fastening member.

[85] To mount the protective cap 37, the protective cap

37 accommodating the sealing member 35 may be pushed toward the

antenna 20 having the corresponding connector 21 or a housing of

the RRU 40 to be brought into contact with the antenna 20 or the

housing of the RRU 40 or may be fastened with the antenna 20 or

the housing of the RRU 40 by using a separate fastening member.

[86] The sealing member 35 may prevent moisture

permeation but may also be formed of a flexible material and thus

be easily damaged by a bird's peak or the like. Therefore, the

exterior of the sealing member 35 may be closed with the protective

cap 37 accommodating the sealing member 35, thereby minimizing

physical damage.

[87] FIGS. 5 through 8 illustrate a process of connecting

a coaxial cable assembly 30 to an antenna 20, according to the

present disclosure.

[88] In order to connect the antenna 20 and the RRU 40

through the coaxial cable assembly 30 according to the present

disclosure, first, the protective cap 37 and the sealing member 35

of the coaxial cable assembly 30 may be pushed backward to the rear

of the coaxial connector 31 and the coaxial connector 31 at an end

of the coaxial cable may be fastened with the corresponding

connector 21 of the antenna 20, thereby completing electrical

connection as illustrated in FIGS. 5 and 6.

[89] As illustrated in FIG. 7, the sealing member 35 may

be pushed to a connector connection portion to seal the connector

connection portion and an end of the heat shrinkable tube 33 facing

the coaxial connector 31 together.

[90] In addition, as illustrated in FIG. 8, the

protective cap 37 may be pushed toward the connector connection

portion to complete connection of the coaxial cable assembly 30

and the antenna 20.

[91] Because the sealing member 35 is formed of a

flexible material, when the protective cap 37 is pushed, the

sealing member 35 is press-fitted into the protective cap 37 and

thus the protective cap 37 may be fixed by the sealing member 35,

and the protective cap 37 may be fixed onto the antenna 20, the

housing of the RRU 40, or the like by using a separate fastening

member.

[92] FIGS. 9 and 10 are a side view and a cross-sectional

view of a sealing member 35 of a coaxial cable assembly 30 according

to the present disclosure.

[93] As illustrated in FIGS. 9 and 10, the entrance 357

and the exit 351 may be provided at both ends of the sealing member

35, and inner diameters d3 and dl of the entrance 357 and the exit

351 may be set to be less than the outer diameter of the coaxial

cable on which the heat shrinkable tube 33 is mounted so as to seal

an outer circumferential surface of the coaxial cable, a connector,

or the like passing through the entrance 357 and the exit 351 while

being brought in close contact therewith.

[94] The sealing member 35 is mainly configured to seal

an interface between each of the coaxial connectors 31 connected

to both ends of the coaxial cable and the corresponding connector

21, and the tube expansion part 353 with an increased inner diameter

may be provided to accommodate the interface between the coaxial

connector 31 and the corresponding connector 21 between the

entrance 357 and the exit 351 of the sealing member 35 when it is

considered that an outer diameter of a connector or a connector

connection portion is larger than that of the coaxial cable.

[95] In general, the coaxial connector 31 and the

corresponding connector 21 are provided with screw type fastening

means and thus a diameter of the connector connection portion is

larger than a diameter of a cable due to a fastening screw.

Therefore, the sealing member 35 may be provided with the tube

expansion part 353 in consideration of an increase in the diameter

of a connector fastening portion, thereby stably accommodating the

connector connection portion. An inner diameter d2 of the tube

expansion part 353 of the sealing member 35 may be larger than

inner diameters of the other parts of the sealing member 35.

[96] As illustrated in FIGS. 9 and 10, the tube expansion

part 353 of the sealing member 35 may be provided closer to the exit 351 of the sealing member 35 facing the coaxial connector 31 than the entrance 357 of the sealing member 35.

[97] The tube expansion part 353 is a space in which the

connector connection portion is accommodated while the sealing

member 35 is mounted and the corresponding connector 21 of the

antenna 20 or the RRU 40 is directly connected to the antenna 20

or the housing of the RRU 40. Thus, the tube expansion part 353

of the sealing member 35 may be provided closer to the exit 351 of

the sealing member 35 to correspond to a position of the connector

connection portion.

[98] The exit 351 of the sealing member 35 seals a body

of the corresponding connector 21 while the sealing member 35 is

mounted and the entrance 357 thereof seals the outer

circumferential surface of the coaxial cable on which the heat

shrinkable tube 33 is mounted, and therefore, the inner diameter

dl of the exit 351 may be larger than the inner diameter d3 of the

entrance 357.

[99] In addition, the entrance 357 and the exit 351 of

the sealing member 35 are air-tightly closed when the sealing

member 35 is mounted, because the sealing member 35 includes the

entrance 357 and the exit 351 and the inner diameters d3 and dl of the entrance 357 and the exit 351 are less than the outer diameter of the coaxial cable on which the heat shrinkable tube 33 is mounted.

[100] Therefore, an empty space may occur in the sealing

member 35 when the sealing member 35 is mounted on the connector

connection portion, and thus, interference may occur due to the

volume of the sealing member 35 when a cap member is mounted. In

order to solve this problem, when the outer circumferential surface

of the sealing member 35 is pressed to remove the empty space in

the sealing member 35 while the sealing member 35 is mounted, the

sealing member 35 may be maintained in a shrunk state and

workability of mounting the cap member may be improved when the

cap member is mounted in the shrunk state of the sealing member

35.

[101] As illustrated in FIGS. 9 and 10, a plurality of

protruding ribs 335r may be provided on a region of the sealing

member 35 excluding the expansion portion 353 in a circumferential

direction to prevent the sealing member 35 from slipping during

mounting of the sealing member 35.

[102] FIG. 11 is a cross-sectional view of a state in

which a sealing member 35 and a cap member of a coaxial cable

assembly according to the present disclosure are mounted.

[103] The protruding ribs 335r may have a function of

fixing or supporting the protective cap to be prevented from

slipping when the protective cap is mounted after the mounting of

the sealing member 35 on the connector connection portion, as well

as a function of preventing the sealing member 35 from slipping

when the sealing member 35 is mounted on the connector connection

portion.

[104] That is, as illustrated in FIG. 11, at least one

locking groove 37g may be provided in an inner circumferential

surface of the protective cap to catch at least one protruding rib

335r of the sealing member 35, so that the protruding ribs 335r of

the sealing member 35 may be placed in the locking grooves 37g

while the protective cap is mounted outside, thereby preventing

the protective cap from slipping.

[105] As described above, the protective cap may be

configured to be fixed by press-fitting the sealing member 35 of a

flexible material thereinto, and an additional mechanical locking

structure may be added to prevent the cap member from slipping,

thereby stabilizing a mounted state of the cap member.

[106] In addition, as illustrated in FIG. 11, the sealing

member 35 includes the plurality of ring-shaped protruding ribs

335r. When the protective cap is mounted surrounding the sealing member 35, the protruding rib 335r adjacent to the entrance 357 of the sealing member 35 among the plurality of protruding ribs 335r may be placed in the locking groove 37g, so that a state of the protruding rib 335r being caught by the locking groove 37g may be maintained while the cap member is tightly joined toward a connector.

[107] A coaxial cable assembly according to the present

disclosure includes a cable protection tube to prevent damage

thereto due to birds' attacks even when installed on the top of a

base station tower, thereby minimizing or preventing damage to a

coaxial cable.

[108] The coaxial cable assembly of the present disclosure

includes a sealing member to seal a connector connection portion

when installed outdoors, thereby minimizing equipment failure or

corrosion due to moisture permeation.

[109] In addition, according to the coaxial cable assembly

of the present disclosure, a process of mounting the sealing member

for sealing the connector connection portion and a protective cap

for protecting the outside of the sealing member may be performed

without additional tool, and the sealing member which is flexible

and elastic may be press-fitted into the protective cap, thereby

improving workability at a base station tower.

[110] While the present disclosure has been described

above with respect to exemplary embodiments thereof, it would be

understood by those of ordinary skilled in the art that various

changes and modifications may be made without departing from the

technical conception and scope of the present disclosure defined

in the following claims. Thus, it is clear that all modifications

are included in the technical scope of the present disclosure as

long as they include the components as claimed in the claims of

the present disclosure.

[111] Throughout this specification and the claims which

follow, unless the context requires otherwise, the word "comprise",

and variations such as "comprises" and "comprising", will be

understood to imply the inclusion of a stated integer or step or

group of integers or steps but not the exclusion of any other

integer or step or group of integers or steps.

[112] The reference in this specification to any prior

publication (or information derived from it), or to any matter

which is known, is not, and should not be taken as an acknowledgment

or admission or any form of suggestion that that prior publication

(or information derived from it) or known matter forms part of the

common general knowledge in the field of endeavor to which this

specification relates.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A coaxial cable assembly comprising:

a coaxial cable;

coaxial connectors connected to both ends of the coaxial

cable;

a cable protection tube surrounding an outside of the coaxial

cable to expose a predetermined end region of the coaxial cable so

as to prevent damage to the coaxial cable;

a sealing member configured to seal an interface between the

coaxial connector and a corresponding connector coupled with the

coaxial connector, the sealing member being provided in an elastic

pipe form; and

a protective cap configured to accommodate and close the

sealing member in a direction toward the corresponding connector

after the sealing member is mounted thereon,

wherein the protective cap is fixed by the sealing member,

wherein the sealing member comprises a plurality of

protruding ribs configured to prevent the sealing member from

slipping, and

wherein the protective cap comprises at least one locking

groove configured to catch at least one protruding rib of the sealing member and the at least one locking groove being provided in an inner circumferential surface of the protective cap.

2. The coaxial cable assembly of claim 1, further comprising

a heat shrinkable tube configured to surround and close connection

portions of the coaxial connectors connected to both ends of the

coaxial cable, starting from both end regions of the cable

protection tube.

3. The coaxial cable assembly of claim 2, wherein the

sealing member comprises an entrance and an exit at both ends

thereof, wherein inner diameters of the entrance and the exit are

less than an outer diameter of the coaxial cable on which the heat

shrinkable tube is mounted.

4. The coaxial cable assembly of claim 3, further comprising

a tube expansion part provided between the entrance and the exit

of the sealing member to accommodate the interface between the

coaxial connector and the corresponding connector, the tube

expansion part having an enlarged inner diameter.

5. The coaxial cable assembly of claim 4, wherein the tube

expansion part of the sealing member is provided closer to the exit

facing the coaxial connector than the entrance.

6. The coaxial cable assembly of claim 4, wherein the inner

diameter of the exit of the sealing member is larger than that of

the entrance of the sealing member.

7. The coaxial cable assembly of claim 4, the plurality of

protruding ribs being provided on a region of the sealing member

other than the tube expansion part in a circumferential direction.

8. The coaxial cable assembly of claim 1, wherein the

sealing member comprises a plurality of ring-shaped protruding ribs,

wherein a protruding rib adjacent to the entrance among the

plurality of protruding ribs is placed in the locking groove when

the protective cap is mounted surrounding the sealing member.

9. The coaxial cable assembly of claim 4, wherein the

sealing member is maintained in a shrunk state when an outer

circumferential surface thereof is pressed to remove an inner empty

space of the sealing member while the sealing member is mounted.

10. The coaxial cable assembly of claim 1, wherein the

coaxial cable assembly is configured to connect a remote radio unit

(RRU) and an antenna in a remote radio head (RRH) base station

system.

11. A remote radio head (RRH) base station system comprising:

a terminal box configured to split at least one optical fiber

and power line composite cable connected thereto, wherein the at

least one optical fiber and power line composite cable comprises a

plurality of power units and a plurality of optical units for

supplying power and data from a power supply unit (PSU) and a

baseband processing unit (BBU) on the earth;

a remote radio unit (RRU) connected to the terminal box, at

least one power unit, and a jumper cable including at least one

unit;

an antenna configured to transmit a radio-frequency (RF)

signal to and receive an RF signal from the RRU; and

the coaxial cable assembly of any one of claims 1 to 10, the

coaxial cable assembly being configured to connect the RRU and the

antenna.

Fig. 1 Drawings 1/10

Fig. 2 2/10

Fig. 3 3/10

Fig. 4 4/10

Fig. 5 5/10

Fig. 6 6/10

Fig. 7 7/10

Fig. 8 8/10

Fig. 9

Fig. 10 9/10

Fig. 11 10/10