GB2380322A

GB2380322A - Support for both cellular telephone antennae and overhead power lines

Info

Publication number: GB2380322A
Application number: GB0114990A
Authority: GB
Inventors: Nicholas David Maggs
Original assignee: ESBI ENGINEERING
Current assignee: ESBI ENGINEERING
Priority date: 2001-06-20
Filing date: 2001-06-20
Publication date: 2003-04-02
Anticipated expiration: 2021-06-20
Also published as: GB2380322B; GB0114990D0

Abstract

An antenna support 2 is installed adjacent a pole 1 of an existing overhead power line. Cellular telephone antenna elements 21, 22 are mounted on an upper part of the antenna support 2 and a base station 24 is installed at the foot of the antenna support 2. The conductors of the existing overhead power line are transferred from the pole 1 to the antenna support 2. A connection between the conductors and the base station 24 is established, through a transformer 26 mounted on the antenna support 2 if voltage reduction is necessary, so as to provide power to the base station 24, and the pole 1 is removed.

Description

Title-Cellular Telephone Antenna and Method of Installation of the same This invention relates to the field of cellular telephony, and in particular to an antenna for use in that field and to a method for the installation of such an antenna.

Cellular telephony depends on the presence on the ground of a sufficient density of antennae, and the growth of cellular telephony networks in recent years has seen the installation of huge numbers of such antennae across the whole area served by the network. Typically such an antenna is mounted on a pole or tower approximately 15m in height.

As the use of cellular telephony increases, the need for more and more antennae to be installed intensifies. The increased volume of calls made may require "cells", each of which will generally be associated with a single antenna, to become smaller, leading to a greater number of cells and a corresponding need for a greater number of antennae. It may also be necessary or desirable to install antennae to extend a network into areas of hitherto low signal strength (so-called "black spots"). When new networks are established, this may lead to a requirement for wholesale installation of new antennae.

Cellular telephone antennae are often unsightly and their installation is resisted by local residents and may be prevented by planning regulations or similar considerations. In addition, each antenna will generally be associated with a ground-mounted base station. It is necessary to provide a power supply for the base station and this may require the installation of an overhead power (OHP) line to bring such power to the antenna and/or the laying of an underground cable. In either event, the environmental impact of installation of the antenna is magnified.

There has now been devised an improved form of cellular telephone antenna, and a method for its installation, which overcome or substantially mitigate the above-mentioned and/or other disadvantages of the prior art.

According to a first aspect of the invention, there is provided a method for the installation of a cellular telephone antenna, which method comprises the steps of (a) installing an antenna support adjacent a pole of an existing overhead power line ; (b) mounting antenna elements on an upper part of the antenna support; (c) installing a base station at the foot of the antenna support; (d) transferring the conductors of the existing overhead power line from the pole to the antenna support; (e) establishing a connection between said conductors and the base station so as to provide power to the base station; and (f) removing said pole.

It will be appreciated that the steps of the method described above may be carried out in various orders. For instance, the antenna elements may be mounted on the antenna support at any one of a number of suitable points during the procedure. Similarly, the base station may be installed at any one of a number of stages of the installation procedure.

The antenna support is most preferably a wooden pole. Such a support is in keeping with the poles widely used in 11 kV and low voltage overhead power transmission lines, is aesthetically less obtrusive than alternatives such as lattice towers, and is also electrically insulating. Wooden poles may also offer advantages In terms of cost. Nonetheless, appropriately treated wooden poles may have structural characteristics and durability comparable to, or better than, those of steel poles or other alternatives.

The antenna support is preferably of greater height than the support poles utilised in the OHP line, so that the antenna elements can be mounted above the

conductors of the OHP line, while maintaining the height at which the conductors are connected to the antenna support equal to that at which they were connected to the OHP pole from which they are moved in the course of the installation.

Connection of the conductors of the existing OHP line to the antenna support is preferably by means of a suitably formed cross-arm or bracket mounted on the antenna support. Such a cross-arm is preferably mounted at a height corresponding to the height at which the conductors are connected to the poles in the existing OHP line, which is normally 10m. Preferably, the antenna support has a height in excess of 12m, most preferably approximately 15m.

The antenna elements may be of generally conventional form, eg 2-or 3-panel antennae suitable for mounting equiangularly around the antenna support, or integrated cluster antennae suitable for mounting coaxially with the top of the antenna support, as well as microwave transmission dishes etc.

The antenna elements are preferably connected to the base station by means of cabling running from the antenna elements down the antenna support and then via underground ducts to the base station. The base station is most preferably located close to (ie within a few metres of) the foot of the antenna support, but may be somewhat more remote from the antenna support, eg if local terrain conditions require a greater separation.

Where the voltage of the overhead power line is greater than that which is suitable for supply to the base station, a transformer is required, and is preferably mounted on the antenna support. The transformer is connected to the appropriate conductors of the overhead power transmission line, and the stepped-down output voltage is supplied to the base station.

The cellular telephone antenna installed in accordance with the method described above represents a further aspect of the invention, according to which there is provided a cellular telephone antenna comprising antenna elements

mounted on an antenna support, the antenna support further supporting the conductors of an overhead power transmission line, the antenna elements being positioned above said conductors, and said conductors being connected to a base station positioned at the foot of said antenna support.

As described above, the antenna support is most preferably a wooden pole. The overhead power transmission line is generally an 11 kV or a low voltage (eg 415V three-phase) power transmission line.

The invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which Figure 1 is a schematic view, not to scale, of part of an existing 11 kV overhead power transmission line; Figures 2 to 5 show schematically stages in the replacement of a support pole of the overhead power transmission line with a first embodiment of an antenna support according to the invention; Figure 6 is a more detailed view of the first embodiment of the antenna support according to the invention, after installation ; and Figure 7 is a view similar to Figure 6, but of a second embodiment of an antenna support according to the invention, installed in a low voltage overhead power line.

Referring first to Figure 1, an 11 kV overhead power transmission line comprises a series of wooden poles 1. Each pole 1 is provided at its top with a crosspiece 11, which carries three insulating bushings 12 to which the three cables of the transmission line are attached. Figure 1 is not to scale : in practice, the separation of poles 1 may be of the order of 100m or more. The height of each pole 1 is approximately 10m.

In accordance with the invention, the installation of a cellular telephone antenna involves replacement of one of the poles 1 of the overhead power transmission line.

In a first stage of installation of the antenna (Figure 2), a wooden support pole 2 is installed adjacent one of the poles 1 of the 11 kV overhead power transmission line. The support pole 2 has a height of 15m, thus extending 5m above the pole 1 alongside which it is positioned. Most preferably, the support pole 2 is positioned in line with the poles 1 of the overhead power transmission line, appropriate precautions being taken to deal with contact of the support pole 2 and associated components with the live conductors of the overhead power transmission line.

After the support pole 2 has been fixed in position, antenna elements 21,22 of conventional form are mounted near its top and the associated cabling 23 (see Figure 6) run down the support pole 2 in appropriate trunking. The cabling 23 is connected, via underground ducts, into a base station 24, which is installed close to the foot of the support pole 2.

Also mounted on the support pole 2 are a cross-arm 25, a transformer 26, a fuse 27 and an anti-climbing collar 28.

The cross-arm 25 is positioned approximately 10m above ground level, thereby corresponding in height to the cross-piece 11 of the pole 1 alongside which the support pole 2 is installed. The cross-arm 25 carries three bushings 29, one of which is mounted at each end of the cross-arm, and the third of which is offset from the centre of the cross-arm so as not to interfere with the cabling 23 that runs down the support pole 2.

The transformer 26 is adapted to reduce an 11 kV voltage taken from the overhead power transmission line to a normal mains voltage suitable for supply to the base station 24. Bushings on the top of the transformer 26 are connected to

two of the bushings 29 on the cross-arm 25. The stepped-down output voltage from the transformer 26 is applied to the base station 24 via cabling 30 and the fuse 27.

Below the anti-climbing collar 28, all cables 23,30 are housed in a protective sheath. The cables then enter ducts below ground that lead into the base station 24 Mounting of the various components upon the support pole 2 is facilitated by the fitting of all appropriate bracketry on the support pole 2 prior to installation of the support pole 2 alongside the pole 1.

Once all components have been installed on the support pole 2, the 11kV overhead power transmission line is temporarily shut down. The conductors making up the overhead power transmission line are then transferred from the bushings 12 on the cross-piece 11 of the pole 1 alongside which the support pole has been installed to the corresponding bushings 29 on the cross-arm 25 of the support pole 2 (see Figure 4).

Once the conductors have been transferred to the cross-arm 25 of the newly installed antenna support pole 2, the overhead power transmission line may once again go live, the pole 1 alongside the support pole 2 then being redundant. The pole 1 may then be removed (see Figure 5), effectively being replaced in the overhead power transmission line by the antenna support pole 2.

Because the net result of these operations is the replacement of one pole (namely the pole 1 of the existing overhead power transmission line) with another (the antenna support pole 2), the environmental impact of the new installation is minimised. As the antenna support pole 2 effectively becomes part of an existing overhead power distribution line, there is no need for the installation of a new branch on a power distribution line to bring power to the antenna base station 24.

Furthermore, since it is only the final stage of installation of the antenna support

pole 2 that requires any operations to be carried out on the conductors of the existing overhead power transmission line, the initial stages of installation can be carried out without interrupting the supply of electricity along that line. The circuit outage necessary to complete the installation is therefore rather brief, as is also the case for any circuit outages necessary for post-installation maintenance of the antenna. Indeed, it may be possible to undertake maintenance under live conditions, using precautionary measures that are known per se.

Figure 7 shows a view similar to Figure 6, but of a second embodiment of a cellular telephone antenna installation according to the invention. This embodiment is installed in an existing 415V (low voltage) overhead power transmission line and so no pole-mounted transformer is required. In other respects, the configuration and installation of this embodiment are as for that described above. The overhead power transmission line consists of four conductors (three phases plus earth).

The completed installation comprises a wooden support pole 31, again of 15m height, on which are installed antenna elements 32,33 with cabling 34, and an anti-climbing collar 35. Power is tapped directly from the appropriate conductors of the overhead power line 36, via a protective sheath 37 on the support pole 31 to the base station (not shown).

Claims

Claims 1. A method for the installation of a cellular telephone antenna, which method comprises the steps of (a) installing an antenna support adjacent a pole of an existing overhead power line ; (b) mounting antenna elements on an upper part of the antenna support ; (c) installing a base station at the foot of the antenna support; (d) transferring the conductors of the existing overhead power line from the pole to the antenna support; (e) establishing a connection between said conductors and the base station so as to provide power to the base station; and (f) removing said pole.
2. A method as claimed in Claim 1, wherein the antenna support is a wooden pole.
3. A method as claimed in any preceding claims, wherein the antenna support is of greater height than the pole of the existing overhead power line.
4. A method as claimed in Claim 3, wherein the antenna elements are mounted above the conductors of the existing overhead power line
5. A method as claimed in any preceding claims, wherein the conductors are connected to the antenna support at a height equal to that at which they were connected to the pole of the existing overhead power line.
6. A method as claimed in any preceding claims, wherein the connection of the conductors of the existing overhead power line to the antenna support is by means of a suitably formed cross-arm or bracket mounted on the antenna support.

<Desc/Clms Page number 9>
7. A method as claimed in Claim 6, wherein the cross-arm is mounted at a height corresponding to the height at which the conductors are connected to the poles in the existing overhead line.
8. A method as claimed in any preceding claim, wherein the antenna support has a height in excess of 12m.
9. A method as claimed in any preceding claim, wherein the antenna elements include 2-panel antennae.
10. a method as claimed in any preceding claim, wherein the antenna elements include 3-panel antennae.
11. A method as claimed in Claim 9 or Claim 10, wherein the antenna elements are mounted at equiangularly spaced positions around the antenna support.
12. A method as claimed in any preceding claim, wherein the antenna elements include integrated cluster antennae.
13. A method as claimed in Claim 12, wherein the antenna elements are mounted coaxially with the top of the antenna support.
14. A method as claimed in any preceding claim, wherein the antenna elements include microwave transmission dishes.
15. A method as claimed in any preceding claim, wherein the antenna elements are connected to the base station by means of cabling running from the antenna elements down the antenna support and then via underground ducts to the base station.

<Desc/Clms Page number 10>
16. A method as claimed in any preceding claim, wherein the base station is located adjacent to the foot of the antenna support.
17. A method as claimed in any preceding claim, wherein the voltage of the overhead power line is greater than that which is suitable for supply to the base station.
18. A method as claimed in Claim 17, wherein a transformer is connected to the appropriate conductors of the overhead power transmission line, and the stepped-down output voltage is supplied to the base station.
19. A method as claimed in Claim 18, wherein the transformer is mounted on the antenna support.
20. A method as claimed in any preceding claim, wherein the overhead power line is an 11 kV power transmission line.
21. A method as claimed in any one of Claims 1 to 20, wherein the overhead power line is a low voltage power transmission line.
22. A cellular telephone antenna comprising antenna elements mounted on an antenna support, the antenna support further supporting the conductors of an overhead power transmission line, the antenna elements being positioned above said conductors, and said conductors being connected to a base station positioned at the foot of said antenna support.
23. A cellular telephone antenna as claimed in Claim 22, wherein the antenna support is a wooden pole.
24. A cellular telephone antenna as claimed in Claim 22 or Claim 23, wherein the conductors of the existing overhead power line are connected to the antenna

<Desc/Clms Page number 11>

support by a suitably formed cross-arm or bracket mounted on the antenna support.
25. A cellular telephone antenna as claimed in any one of Claims 22 to 24, wherein the antenna support has a height in excess of 12m.
26. A cellular telephone antenna as claimed in any one of Claims 22 to 25, wherein the antenna elements include 2-panel antennae.
27. A cellular telephone antenna as claimed in any one of Claims 22 to 26, wherein the antenna elements include 3-panel antennae.
28. A cellular telephone antenna as claimed in Claim 26 or Claim 27, wherein the antenna elements are mounted at equiangularly spaced positions around the antenna support.
29. A cellular telephone antenna as claimed in one of Claims 22 to 28, wherein the antenna elements include integrated cluster antennae.
30. A cellular telephone antenna as claimed in Claim 29, wherein the antenna elements are mounted coaxially with the top of the antenna support.
31. A cellular telephone antenna as claimed in any one of Claims 22 to 30, wherein the antenna elements include microwave transmission dishes.
32. A cellular telephone antenna as claimed in any one of Claims 22 to 31, wherein the antenna elements are connected to the base station by cabling running from the antenna elements down the antenna support and then via underground ducts to the base station.

<Desc/Clms Page number 12>
33. A cellular telephone antenna as claimed in any one of Claims 22 to 32, wherein the voltage of the overhead power line is greater than that which is suitable for supply to the base station.
34 A cellular telephone antenna as claimed in Claim 33, wherein a transformer is connected to the appropriate conductors of the overhead power line, and the stepped-down output voltage is supplied to the base station
35 A cellular telephone antenna as claimed in Claim 34, wherein the transformer is mounted on the antenna support.
36 A cellular telephone antenna as claimed in any one of Claims 22 to 35, wherein the overhead power line is an 11 kV power transmission line.
37 A cellular telephone antenna as claimed in any one of Claims 22 to 35, wherein the overhead power line is a low voltage power transmission line.
38 A method for the installation of a cellular telephone antenna substantially as hereinbefore described and as illustrated in the accompanying Figures.
39. A cellular telephone antenna substantially as hereinbefore described and as illustrated in the accompanying Figure 6.
40. A cellular telephone antenna substantially as hereinbefore described and as illustrated in the accompanying Figure 7.