KR102712270B1 - Composite cable and microwave system having thereof - Google Patents

Abstract

The present invention relates to a composite cable and a microwave system including the same, which is easy to install and maintain because the number of cables used in a microwave system is minimized.

Description

Composite cable and microwave system having thereof {Composite cable and microwave system having thereof}

The present invention relates to a composite cable and a microwave system including the same. More specifically, the present invention relates to a composite cable and a microwave system including the same, which are easy to install and maintain because the number of cables used in a microwave system is minimized.

A microwave system is a system that wirelessly transmits and receives data using microwave frequencies, and a microwave transmission system (M/W transmission system) refers to a system that can transmit digital signals using microwave radio frequency (4–18 GHz) signals.

Microwave systems are used to relay long distances at low cost in areas such as the sea, valleys, and mountains where it is difficult to build wired communication lines along the communication line route. They are widely used to connect land and islands or areas with few terrestrial obstacles.

FIG. 1 is a schematic diagram of a conventional microwave system. A mobile communication system utilizing such a microwave system converts a data signal transmitted from a communication base station (400, 400') to an RF signal at a BTS (300, 300', Base Transceiver Station) of the base station (400, 400'). The BTS (300, 300') of the base station (400, 400') transmits the RF signal to a base station antenna (200a, 200a'). The antenna (200a or 200a') transmits a radio signal in the form of a microwave to an antenna (200a' or 200a) of an opposing base station. Such transmission and reception of radio signals via microwaves is performed in both directions, so that a high-speed communication network can be constructed at a low cost in an environment where it is difficult to construct wired lines.

At this time, conventionally, the BTS (300, 300') and antenna (200a, 200a') of the base station were connected with a coaxial feed line (100a, 100a'), but the coaxial feed line (100a, 100a') had a problem in that as the cable length increased, signal loss increased.

Therefore, when the antenna (200a, 200a') is installed on a tower several tens of meters high, the loss increases in the coaxial feed line (100a, 100a') connecting the ground base station (400, 400') and the antenna (200a, 200a'), and the signal provided from the base station (400) is attenuated and does not reach the signal intensity required by the antenna (200a, 200a') due to the signal loss of the coaxial feed line (100a, 100a'). Therefore, a TMA (not shown, Tower Mounted Amplifier) is applied to compensate for and amplify this. However, since the TMA consumes relatively much power to amplify the signal, there was a problem in that it required a lot of maintenance costs and its efficiency was low when viewed from the perspective of the overall system.

Meanwhile, to solve these problems, base station facilities have also evolved with the evolution of FTTx (Fiber to the X) and miniaturization of repeater equipment. Compared to coaxial cables, optical cables have a very small signal attenuation according to cable length, so they transmit optical signals all the way to just before the base station antenna to minimize signal loss, and a technology called RRH (Remote Radio Head) has emerged that converts optical signals containing wireless communication target data into RF signals that can be radiated just before the antenna.

RRH (Remote Radio Head) is a device that complements the inefficient power consumption and maintenance of conventional mobile communication base stations using TMA. RRH is configured to separate the remote RF unit (RRU) from the conventional BTS, place it on the antenna side of the base station tower, and remotely control it.

Since these Remote RF Units (RRUs) can be mounted on Outdoor Units (ODUs) equipment and installed near the base station antenna on the top of the base station tower, the length of the coaxial feed line for supplying the signal converted into the Remote RF Unit (RRU) RF signal to the antenna is minimized, so RF signal attenuation that occurs when transmitting RF signals through the coaxial line does not become a problem, the amount of signal attenuation until just before radiation is minimized, and the need for the TMA that previously consumed a lot of power is eliminated.

FIGS. 2 and 3 illustrate an outdoor unit (250, Outdoor Unit) equipped with a remote RF unit (RRU) in an RRH-type microwave system, connected to an optical cable (10), a power cable (20), and a twisted pair cable (60). As described above, by separating the RRU from the BTS, the coaxial feed line (100 in FIG. 1) connecting the BTS (300) and the antenna (200) of FIG. 1 is not applied, and only the outdoor unit (250) and the antenna (200), which can be assembled integrally, are connected to each other with a coaxial cable (not shown in the structure where the antenna and the outdoor unit are directly connected), thereby minimizing the length of the coaxial cable.

However, as shown in Fig. 2, since it is connected with multiple cables (100b) including BTS on the ground, optical cables (10), power cables (20), and twisted pair cables (60), problems such as easy damage to the cables, difficulty in maintenance, increased cable installation costs, and difficulties in continuous cable management may occur.

In addition, due to recent changes in the communication environment, there are many cases where a MIMO (Multi input multi output) system must be configured, and as illustrated in FIG. 3, when configuring a microwave system capable of MIMO (Multi input multi output) communication, the outdoor units (250, Outdoor Unit) provided to each antenna (200a, 200b) must be additionally connected and used with an optical cable (10) for data optical communication, a twisted pair cable (60), or a coaxial cable (90) for synchronization or signal sharing of RF signals. Therefore, in a system for implementing MIMO, more cables may be connected in a complex manner than in the SISO system of FIG. 1.

In this way, when a cable connecting the ground base station and the outdoor unit of each antenna and an independent optical cable (10), power cable (20), twisted pair cable (60) or coaxial cable (90) for interconnecting the outdoor units of each antenna are applied, the cabling near the base station tower antenna becomes complicated, becomes a cause of frequent breakdowns, makes system maintenance difficult and causes an increase in costs.

The present invention aims to provide a composite cable and a microwave system including the same, which are easy to install and maintain because the number of cables used in a microwave system is minimized.

In order to solve the above problem, the present invention provides a composite cable which is connected to a microwave antenna constituting a microwave system and connected to an outdoor unit (ODU) equipped with a remote RF unit (RRU), the composite cable including: an optical unit including at least one optical fiber for transmitting an optical signal; a subunit including at least one conductor for transmitting power or a signal; and a cable jacket surrounding the optical unit and the subunit.

In addition, at least one end of the composite cable is provided with a terminal unit for branching the optical unit or the sub-unit, and the optical unit or the sub-unit can be branched through the terminal unit before connecting to the outdoor unit.

In this case, the optical unit may be a loose tube type optical unit equipped with a plurality of optical fibers for transmitting optical signals.

And, the above subunit may be a twisted pair communication unit.

Here, the composite cable connects the ground base station equipment and the outdoor unit, the optical unit transmits an optical signal including wireless transmission and reception data, and the twisted pair communication unit can transmit and receive a control signal of the antenna or the ODU.

In addition, the composite cable connects the outdoor unit equipped with a pair of antennas respectively, the optical unit transmits an optical signal including wireless transmission and reception data, and the twisted pair communication unit can transmit and receive a control signal of the antenna or the ODU.

And, the twisted pair communication unit may be a 4-pair STP or UTP cable of Category 5E grade or higher.

In this case, the subunit may be a power unit.

And, the power unit may include at least one unit power unit including at least one conductor line and an insulator that insulates the conductor line; and a power unit tube that accommodates a plurality of the unit power units.

In addition, the composite cable connects the ground base station equipment and the outdoor unit, the optical unit transmits an optical signal including wireless transmission and reception data, and the power unit can supply power to the ODU.

In this case, multiple power units may be provided.

And, the above subunit can be a coaxial cable.

Here, the composite cable connects the outdoor units, each of which is equipped with a pair of antennas, the optical unit transmits an optical signal including wireless transmission/reception data, and the coaxial cable can transmit and receive RF signals between the outdoor units.

In addition, in order to solve the above problem, the present invention can provide a microwave system including: at least one microwave antenna; at least one outdoor unit equipped with an RRU (Remote RF Unit) respectively provided in the microwave antenna; and the above-described composite cable for connecting ground base station equipment and the ODU.

In addition, the microwave antenna and the ODU are each provided in multiple units, and the outdoor unit provided to each of at least one pair of antennas can be connected with the composite cable described above.

According to the composite cable according to the present invention, transmission of an optical signal, power, control signal or RF signal can be possible with one cable in a microwave system.

In addition, according to the composite cable according to the present invention, the number of cables constituting the microwave system is minimized, thereby simplifying the cabling of the microwave system, making it easy to maintain and repair the microwave system, and minimizing the costs of installation, maintenance, repair, and management of the microwave system.

In addition, according to the composite cable according to the present invention, various combinations of optical-electrical composite cables can be provided depending on the purpose of wireless communication, communication capacity, or antenna output.

Figures 1 to 3 illustrate the configuration of a conventional microwave system.
Figures 4 to 7 illustrate a composite cable and a microwave system including the same according to an embodiment of the present invention.
FIGS. 8 and 9 illustrate a composite cable and a microwave system having the same according to another embodiment of the present invention.
FIGS. 10 and 11 illustrate a composite cable and a microwave system having the same according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the embodiments described below are merely described in detail to an extent that a person having ordinary knowledge in the technical field to which the present invention belongs can easily carry out the invention, and this does not mean that the protection scope of the present invention is limited due to this. In addition, in describing various embodiments of the present invention, the same drawing reference numerals will be used for components having the same technical features.

The composite cable (100) according to the present invention can have various internal configurations depending on the connection target or the purpose of the cable.

Hereinafter, a composite cable (100) according to the present invention and a microwave system (1) including the same will be described with reference to the attached drawings.

Figures 4 to 7 illustrate a composite cable (100) and a microwave system (1) equipped with the same according to an embodiment of the present invention.

A composite cable (100) according to the present invention is connected to a microwave antenna (200) of a microwave system (1), is connected to an outdoor unit (250) including a remote RF unit (RRU), and may be configured to include an optical unit (10) including at least one optical fiber (11) for transmitting an optical signal; a subunit including at least one conductor (21) for transmitting power or a signal, and a cable jacket (40) surrounding the optical unit (10) and the subunit.

As described below, the subunit may be a unit that has at least one conductor for transmitting power or a signal (e.g., a control signal or an RF signal, etc.) in addition to an optical signal transmitted by an optical unit, when connecting a ground base station equipment and an outdoor unit, or connecting at least one pair of outdoor units, depending on the connection target or purpose by the composite cable (100) of the present invention. That is, the subunits constituting the composite cable (100) of the present invention have in common that they have at least one conductor for transmitting power or a signal.

For example, the sub-unit may include at least one or more of a power unit (20), a twisted pair communication unit (60), or a coaxial unit (90), as described below, and a plurality of the same sub-units may be provided. This will be described in detail.

In the embodiments shown in FIGS. 4 to 7, the composite cable (100) according to the present invention may be a connecting means for connecting ground-based base station equipment and the outdoor unit (250), and in common, the composite cable (100) may be equipped with at least one optical unit (10), and the sub-unit may be a power unit (20).

Here, 'ground-based base station equipment' may be understood as equipment including a baseband unit (BBU) and a power supply unit (PSU) separated from a remote RF unit (RRU) equipped in an outdoor unit (250: ODU, Outdoor Unit) mounted near a microwave antenna (200) in a conventional RRH-type base station system.

The above optical unit (10) can be responsible for transmitting and receiving optical signals between the ground base station equipment and the outdoor unit (250) or, in the embodiment described below, between a pair of outdoor units (250).

The above optical unit (10) may include a unit optical unit (15) of a loose tube type equipped with a plurality of optical fibers (11) for transmitting an optical signal. The unit optical unit (15) may include a loose tube (12) equipped with at least one optical fiber (11), and may be in the form of a plurality of unit optical units (15) accommodated in an optical unit tube (13).

The above loose tube (12) may be composed of a material such as polybutylene terephthalate (PBT), polypropylene, polyethylene or polyvinyl chloride.

In addition, a filler may be filled into the loose tube (12) constituting the unit light unit (15). For example, a waterproof jelly may be filled, or a filler such as waterproof yarn or aramid yarn may be applied.

In addition, the optical fiber (11) constituting each unit optical unit (15) may be composed of a single-mode optical fiber (SM Optical fiber), and in some cases may be a multi-mode optical fiber (MM Optical fiber).

Additionally, the optical unit (10) may be a tight buffer type optical unit (10).

Accordingly, the optical unit (10) illustrated in FIG. 4 is illustrated as having four unit optical units (15) of a loose tube type accommodated in one optical unit tube (13) to form one optical unit (10), but the number of optical fibers (11) inside one unit optical unit (15) and the number of unit optical units (15) forming one optical unit (10) can be increased or decreased.

The composite cable (100) illustrated in FIGS. 4 and 6 may have at least one power unit (20).

The above power unit (20) may be provided to supply driving power to the microwave antenna (200) or the outdoor unit (250) from ground-based base station equipment.

The above power unit (20) may be configured to include at least one unit power unit (25) including at least one conductor (21) and an insulator (23) that insulates the conductor (21), and a power unit tube (27) that accommodates a plurality of the unit power units (25).

As shown in FIGS. 4 and 6, the conductor (21) may be composed of a stranded conductor made up of stranded small wire conductors, but is not limited thereto.

And, as shown in FIG. 4 and FIG. 6, the empty space (30) around the optical unit (10) and the power unit (20) may be provided with a tensile fiber layer or may be maintained as an empty space. A cable jacket (40) may be provided on the outside of the optical unit (10) and the power unit (20).

The composite cable (100) illustrated in FIG. 4 illustrates an example in which one optical unit (10) and one power unit (20) equipped with two unit power units (25a, 25b) are provided, and the composite cable (100) illustrated in FIG. 6 illustrates an example in which two optical units (10) and two power units (20a, 20b) each equipped with two unit power units (25a, 25b) are provided. The number of optical units (10) and power units (20) can be increased or decreased depending on the amount of data to be transmitted and received and the amount of power required by the microwave system.

The composite cable (100) illustrated in FIGS. 4 and 6 is provided to connect ground base station equipment and the outdoor unit (250), the optical unit (10) transmits and receives an optical signal including wireless transmission and reception target data, and the power unit (20) may be provided to supply power to the outdoor unit (250) or the microwave antenna (200).

In the embodiment illustrated in FIG. 5, to which the composite cable (100) of FIG. 4 is applied, one optical unit (10) and one power unit (20) can be branched from the end of the composite cable (100) and connected to the outdoor unit (250) provided at the rear of the microwave antenna (200), and in the case where the composite cable (100) of FIG. 6 is applied, as illustrated in FIG. 7, one pair of optical units (10a, 10b) and one pair of power units (20a, 20b) can be branched from the end of the composite cable (100) and connected to the outdoor unit (250) provided at the rear of the microwave antenna (200).

And, since the diameter of the conductor (21) constituting the unit power unit (20) of the composite cable (100) illustrated in FIG. 4 and the composite cable (100) illustrated in FIG. 6 or the number of optical fibers (11) provided in the unit optical unit (15) can be increased or decreased, the number of optical units (10) and power units (20) can be selected in order to adjust the filling rate of the optical unit (10) and power unit (20). In addition, the number of optical units (10) and the number of power units (20) can also be configured differently.

At the end of the composite cable (100) of the present invention, a terminal unit (t) for branching a sub-unit such as the optical unit (10) or the power unit (20), or a twisted pair communication unit (60) or a coaxial unit described later is provided, and the composite cable (100) may have a structure in which the optical unit (10) or the sub-unit is branched through the terminal unit (t) before connecting to the outdoor unit (250).

The above terminal unit (t) may have a structure in which the optical unit (10) or the sub-unit, etc. are branched, but moisture penetration into the interior is blocked.

Figures 8 and 9 illustrate a composite cable (100) and a microwave system (1) equipped with the same according to another embodiment of the present invention. Descriptions that overlap with the embodiments referred to in Figures 4 to 7 are omitted.

The embodiment illustrated in FIGS. 8 and 9 may further include a twisted pair communication unit (60) as a subunit, unlike the embodiment illustrated in FIGS. 4 and 5. That is,

The above twisted pair communication unit (60) may have at least one twisted pair, and is not limited to having four twisted pairs as shown in FIG. 8.

The composite cable (100) illustrated in FIG. 8 also connects the ground base station equipment and the outdoor unit (250), and the optical unit (10) transmits an optical signal including wireless transmission and reception data, and the twisted pair communication unit (60) may be provided to transmit and receive a control signal of the microwave antenna (200) or the outdoor unit (250) or a sensing signal by a sensor, etc.

As with the optical unit (10) above, the twisted pair communication unit (60) is also a communication cable, but the wireless transmission/reception data signal through the microwave antenna (200) is transmitted through the optical unit (10), and the control signal for controlling the microwave antenna (200) or the outdoor unit (250) or the sensing signal by the sensor, etc. is transmitted/received through the separate twisted pair communication unit (60), so that the data transmitted/received through the optical unit (10) can be transmitted to the controller for controlling the microwave antenna (200) or the outdoor unit (250) without the photoelectric conversion process and branching device, thereby simplifying the internal configuration of the outdoor unit (250).

And, the twisted pair communication unit (60) is composed of an STP or UTP cable of Cat. 5E grade or higher, which has four twisted pair conductors (61), a separator (63), and a cable jacket layer (65), and can secure a speed that is sufficient for transmitting signals such as bidirectional control signals (or sensing signals). The four twisted pair conductors (61) can form a twisted pair with each conductor in an insulated state.

In the embodiment illustrated in FIG. 9, a terminal unit (t) for branching the optical unit (10), the power unit (20), and the twisted pair communication unit (60) is provided at the end of the composite cable (100), and through the terminal unit (t), the optical unit (10), the power unit (20), and the twisted pair communication unit (60) can be connected in a branched state before connecting the outdoor unit (250) of the composite cable (100).

The embodiment illustrated in FIGS. 8 and 9 may also include an optical unit (10) and a power unit (20), and the optical unit (10) may transmit and receive an optical signal including wireless transmission/reception target data, and the power unit (20) may perform the function of supplying power to the outdoor unit (250) or the microwave antenna (200).

Figures 10 and 11 illustrate a composite cable (100) and a microwave system (1) equipped with the same according to another embodiment of the present invention. Descriptions that overlap with those described with reference to Figures 4 to 9 are omitted.

In the system illustrated in FIG. 11, a pair of microwave antennas (200a, 200b) are each provided with an outdoor unit (250a, 250b), and each outdoor unit (250a, 250b) is connected to ground base station equipment and a composite cable (100) illustrated in FIG. 4, FIG. 6 or FIG. 8, so that it can transmit and receive optical signals, power or control signals.

However, when configuring a microwave system (1) capable of recent MIMO (Multi-input multi-output) communication, each outdoor unit (250a, 250b) equipped on each antenna (200a, 200b) may be interconnected to require synchronization of RF signals or sharing of wireless transmission/reception signals.

As previously described, the number of cables was determined based on the type of signal shared by connecting each outdoor unit (250a, 250b), but the cables can be unified using the composite cable (100) according to the present invention.

The composite cable (150) of the present invention illustrated in FIG. 10 may be a cable for connecting a pair of outdoor units (250a, 250b).

The composite cable (150) connecting a pair of outdoor units (250a, 250b) of the present invention illustrated in Fig. 10 may be equipped with one optical unit (10) for transmitting and receiving or sharing optical signals and at least one coaxial unit (90) for synchronizing RF signals as a subunit.

In addition, a twisted pair communication unit (60) may be provided as an additional subunit for transmitting/receiving or sharing mutual control signals or sensing signals.

The above coaxial unit (90) may have a general coaxial cable structure and may have a structure including an inner conductor (91), an insulator (93), an outer conductor (95), and a covering layer (97), and the signal type shared through the coaxial unit (90) may be an RF signal.

In this way, in order to configure a MIMO (Multi Input Multi Output) system, when a system is configured by connecting a pair of microwave antennas (200a, 200b) and each outdoor unit (250a, 250b) mounted on a pair of microwave antennas (200a, 200b), the connection can be completed with three composite cables (100, 150) as illustrated in FIG. 11. Accordingly, compared to the conventional system using nine cables illustrated in FIG. 3, the cabling of the system can be simplified, system failure due to cable damage can be reduced, and the workability of maintenance can be improved, resulting in cost reduction.

Although this specification has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to modify and change the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

1: Microwave system
100 : Composite Cable
200 : Microwave Antenna
250 : Outdoor Unit

Claims (17)

In a composite cable connected to a microwave antenna constituting a microwave system and connected to an outdoor unit (ODU) equipped with a remote RF unit (RRU),
An optical unit comprising at least one optical fiber for transmitting an optical signal;
A subunit comprising at least one conductor for transmitting power or signals;
A cable jacket surrounding the above optical unit and the above subunit; and,
A composite cable characterized by including a terminal unit for independently branching the optical unit and the sub-unit at the end of the composite cable. delete In the first paragraph,
A composite cable characterized in that the above optical unit is a loose tube type optical unit equipped with a plurality of optical fibers for transmitting optical signals. In the first paragraph,
A composite cable characterized in that the above subunit is a twisted pair communication unit. In paragraph 4,
A composite cable characterized in that the above composite cable connects ground base station equipment and the outdoor unit, the optical unit transmits an optical signal including wireless transmission/reception data, and the twisted pair communication unit transmits and receives a control signal of the antenna or the ODU. In paragraph 4,
The composite cable is characterized in that the above composite cable connects the outdoor unit equipped with a pair of antennas respectively, the optical unit transmits an optical signal including wireless transmission/reception data, and the twisted pair communication unit transmits and receives a control signal of the antenna or the ODU. In paragraph 4,
The above twisted pair communication unit is a composite cable characterized by being a 4-pair Category 5E grade or higher STP or UTP cable. In the first paragraph,
A composite cable characterized in that the above subunit is a power unit. In Article 8,
A composite cable characterized in that the power unit comprises at least one unit power unit including at least one conductor line and an insulator that insulates the conductor line; and a power unit tube that accommodates a plurality of the unit power units. In Article 8,
A composite cable characterized in that the above composite cable connects ground base station equipment and the outdoor unit, the optical unit transmits an optical signal including wireless transmission and reception data, and the power unit supplies power to the ODU. In Article 8,
A composite cable characterized in that the above power unit is provided in multiple units. delete delete At least one microwave antenna;
At least one outdoor unit equipped with an RRU (Remote RF Unit) and each of the above microwave antennas; and,
A microwave system comprising a composite cable according to any one of claims 1, 3 to 11 for connecting ground base station equipment and the outdoor unit. delete In a composite cable connected to a microwave antenna constituting a MIMO microwave system and connected to an outdoor unit (ODU) equipped with a remote RF unit (RRU),
The above composite cable connects at least one pair of outdoor units among a plurality of outdoor units,
An optical unit comprising at least one optical fiber for transmitting an optical signal;
A coaxial unit for transmitting a synchronization signal to at least one pair of outdoor units; and
A composite cable including a cable jacket surrounding the optical unit and the coaxial unit. Multiple microwave antennas;
A plurality of outdoor units, each equipped with a plurality of microwave antennas and having an RRU (Remote RF Unit); and,
A microwave system comprising a composite cable of claim 16 connecting at least one pair of outdoor units among the plurality of outdoor units.

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