AU2020202803A1

AU2020202803A1 - Coaxial cable assembly

Info

Publication number: AU2020202803A1
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: 2021-01-28
Anticipated expiration: 2040-04-28
Also published as: CN112217036A; KR102758197B1; AU2020202803B2; KR20210007116A; CN112217036B

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:

BACKGROUND OF THE INVENTION

Field of the Invention

[01] The present invention relates to a coaxial cable

assembly. More specifically, 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.

Background Art

[01] 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.

la

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

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

SUMMARY OF THE INVENTION

[12] The present invention 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 outoors.

[13] To achieve these objects, the present invention 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]

[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]

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

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.

BRIEF DESCRIPTION OF THE DRAWINGS

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

a coaxial cable assembly according to an embodiment of the present

invention is installed;

[28] 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 invention;

[29] 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 invention;

[30] FIG. 4 illustrates a coaxial cable assembly according to

the invention;

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

coaxial cable assembly to an antenna, according to the present

invention;

[32] 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 invention; and

[33] 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 invention are mounted.

DETAILED DESCRIPTION

[34] Hereinafter, exemplary embodiments of the present

invention will be described in detail with reference to the

accompanying drawings. The present invention is, however, not

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

invention 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

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

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 invention for supplying to

the antenna 20 an RF signal obtained through conversion by the RRU

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 invention 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 invention, 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 invention 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 invention.

[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 invention 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 invention.

FIG. 4 illustrates the coaxial cable assembly 30 according to the

invention.

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

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

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

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

coaxial cable assembly 30 according to the present invention.

[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 invention 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

are structurally exposed to the outside and thus are

continuously exposed to snow and rain, the coaxial cable assembly

according to the present invention 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

invention 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

invention 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 invention

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

invention.

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

the coaxial cable assembly 30 according to the present invention,

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

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 invention.

[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

, and inner diameters dl and d2 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

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

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 invention 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

invention 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 invention

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 invention, 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 invention 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 invention defined in

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

are included in the technical scope of the present invention as

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

the present invention.

[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.

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 13, 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, further comprising

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.

8. The coaxial cable assembly of claim 7, further comprising

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.

9. The coaxial cable assembly of claim 8, 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.

10. 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.

11. 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.

12. 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 11, 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