The present invention regards a method and a system for building a site for a telecommunication antenna, and more particularly a site for a mobile

telecommunication network that can be installed fast in remote places with low cost.

Background of the invention

The present situation regarding building a site for a telecommunication network requires a lot of planning, a lot of merchandise and a large group of people working together in a team with different tasks that have to be performed in the right order. Further, the average time it takes to build such a site is normally around 7 weeks.

This makes the building of such a site very costly, which again leads to the fact that wireless telecommunication networks have relatively low coverage in certain parts of the globe like developing countries.

A problem is that the cost of expanding the coverage in these countries usually is larger even than in industrial countries because of the problems related to infrastructure.

This leads to the fact that not only is the cost a problem regarding these developments, but also the transport of the equipment and personnel.

The personnel and equipment needed for building a site for a telecommunication tower requires with, the state of the art equipment, the following resources: a trained team for installing the antenna, an expert supervisor and a site master, and it is also necessary to perform tests and an analysis on the site.

There is therefore a need for a solution where it is possible to build such a site fast and easily and that can be maintained by the local people in the area.

There is known from WO/2002/025768 an invention concerning a telecommunications mast installation, typically a base station in a cellular telephone network, which includes a mast supporting a telecommunications antenna. A foundation structure supports the mast. The foundation structure is in the form of an enclosed chamber situated at least partially underground and defining an internal space which is accessible to personnel and which accommodates electronic equipment associated with operation of the antenna. For aesthetic and security reasons, it is preferred that the chamber be completely underground. This solution requires a lot of manpower to install and a lot of heavy and costly equipment to be transported to the site and it is also not meant to be taken down easily. Further it doesn't have the possibility to use alternative power sources.

From FR 2861503 Al there is known a tower with a central shaft including vertical sections that are materialized by horizontal units. Two sets of stays are distributed around the shaft, and deployed between a node of the shaft and ground and on both sides of the horizontal units, respectively. The stays have anchor points disposed on the shaft and on an outer edge of a considered horizontal unit, respectively.

The problem with this solution is that, like WO/2002/025768, it takes a large crew a long time to mount this tower and it requires a lot of equipment. Further it is not easy to dismount again and if it need repair the local communities cannot maintain the maintenance of this mast.

This tower has further problems with the possibilities of using other power sources than electricity.

So the problem is that at the present time there is no fast, easy and cost effective way to build or maintain a site for a telecommunication tower in remote places. Further there exists no site that easily can be dismounted so that it can be rebuilt in another location.

Summary

It is therefore an object of the present invention to solve the problems mentioned above by presenting a site that is easy to build, maintain and to dismount again. Further it also has the ability to be powered by other means than being connected to the electricity grid and it can easily be custom fit to different needs.

The present invention consists of ready premade units that easily can be put together, further they can be put together by local non-skilled persons. This is solved by not having to make a foundation for the site. The site itself is held in place not by anchoring the site to the ground, needing heavy machinery, but it is held in place by the weight of the site. The weight of the perimeter enclosure, in this embodiment in the form of a wall, surrounding the site makes sure that the site is held in place.

The invention consists of a foundation of ground beams made of steel with a wall that can either be made in situ or premade and transported in sections to the site to be put together there.

Further the tower and the units controlling the antenna and giving power to the antenna can all be bolted to the ground beams.

It is also possible to mount a gate and barbed wire on top of the wall if it is necessary to protect the area.

This way of mounting the tower makes it also possible to dismount the tower fast and transport it to another place again if it is necessary.

Further it is possible to mount and build the site without using any foundation like cement or sand. The invention can be mounted directly on the ground as it is. Short description of the drawings

Figure 1 gives a view of the foundation of an embodiment of the present invention. Here it can be seen how all the ground beams are bolted together in a predetermined shape.

Figure 2 gives a view of an embodiment of the present invention and shows how further supporting of the ground beams.

Figure 3 gives a view of how a wall can be mounted to the supporting structures.

Figure 4 shows an embodiment of the present invention where the walls are erected with a gate and barbed wire connected.

Figure 5 shows how it is possible to mount the tower itself to the ground beams. Figure 6 shows one solution to how the different equipment is bolted to the ground beams. Figure 7 shows a perspective view of the present invention according to an embodiment of a finished site.

Figure 8 shows a site layout plan of an embodiment of the present invention.

Figure 9 shows an embodiment of how the wall bolts look. Figure 10 shows how the wall bolts are used in connection with the wall and the girders.

Figure 11 shows a side view of an embodiment of the present invention when the tower is fully erected.

Figure 12 shows a detailed side view of an embodiment of the present invention. Detailed description of the drawings The present invention shows a method and an arrangement of a telecommunication tower and how to build a site like this in a short period of time. The present invention is fully adaptable to the customers' needs and specifications and can be both a permanent and a temporary solution. The tower, 501, usually has a height of 15 to 40 meters, but it also has the ability to have a range beyond this. One of the preferred solutions to this is that it requires no foundation and no concrete or sand and the erection and installation can be done fully without machinery.

An average site usually has a build time of 4 - 5 days after the arrival of the materials to the site and the site can be dismantled and re-erected without any waste of material, and to dismantle an average site is usually done in 3 - 4 days. All this gives the site and the present invention an improved price and performance and makes it possible to reach places faster and cheaper than it was possible with prior art.

Figure 1 gives an overview of the foundation of the site. The foundation consists of prefabricated steel beams, 101, preferably cut into size before they arrive at the site.

The steel beam or ground beams, 101 , can be laid straight on the ground with only a minimum of preparation of the ground. It is therefore not necessary to use sand or cement to make a foundation. All of the parts making out this foundation can be hand carried and are usually bolted together. For a more permanent installation the structure can be welded together. The ability to bolt the ground beams together makes the structure easy to mount and easy to dismount again also and makes it possible to build without using heavy machinery since the max load of the steel frame foundation is only 350 kg.

Figure 2 gives a view of how the secondary steel frame structure, 201, is laid out, this is in the form of smaller girders laid in between the primary structure, 101, to give further support and further places to bolt the different equipment to the foundation.

This structure is the one the outdoor BTS (Base Transceiver System) is mounted to, the fuel tank, 401 , and the generator, 701, and so on. These units can be mounted to the steel frame, 101 and 201 , by bolting them to the girders in the way shown in figure 6.

Further the figure 3 shows how the walls, 301, are mounted to the outermost girders, of the primary steel frame, 101, shown in figure 1. By using the walls, 301, in this fashion the size of the steel frame, 101, and the dimension can be reduced since the weight and size of the wall, 301, helps keep the structure in place. The wall, 301, serves therefore two purposes, one it serves as a restriction making it harder for either people or animals to get inn to the site and hurting themselves or destroying the site and two it serves as a solution to holding the structure in place making the foundation lighter which again makes it possible to mount using only hand labour. The fence blocks, 904, themselves are usually at about 80 kg each and a site of 40 meter requires approximately 350 fence blocks, 904. A fence block, 904, can either be prefabricated locally or they can be made on site.

The fence blocks, 904, are like all the other equipment bolted to the steel frame in e.g. the manner shown in figure 9. Figure 4 shows how the structure ready assembled, except for the tower, 501, and it can be seen how the walls, 301, are fitted with a steel fence, 403, on top of the wall, 301, and barbed wire all around the structure. This is optional but can be a safety in remote places where communication is crucial. Communication is often one of the first things to be targeted by enemies in a warlike situation. In figure 5 it can be seen how the tower, 501, is bolted to the steel frame, 101, just like all the other equipment connected to the site.

As it is shown here the tower, 501, is bolted directly to the steel girders of either the first, 101, or the second, 201, steel frame foundation or both. This is one of the solutions to bolting the tower and all the equipment to the frame, but it can be beneficial to use a distance spacer pipe, 602, like the one shown in figure 6.

Here it can be seen that the steel girders, 101, are a galvanized steel beam. Further the steel beams are fitted with steel plate stiffeners, 605, usually in 10 mm steel. The stiffeners, 605, are usually welded between the top and the bottom plates of an I-shaped steel girder. This helps the foundation handle the pressure and the weight of the tower, 501, better since a lot of forces are working on these girders not only because of the weight of the tower, but also because of the forces from the weather working on the tower.

Further it can be seen that the tubular tower leg, 601, is mounted to a distance spacer pipe, 602, made out of e.g. 20 mm steel plate fitted with extra stiffeners, 603. The distance spacer pipe, 602, has a v-cut, 604, which serves as a drain for all the water that comes of the tower in the rain. It is important that this is a part of the structure to prevent corrosion of the material.

Figure 7 gives a perspective view of the site at it looks in the finished state. As it can be seen here the floor of the structure is fitted with grated floor panels making it easier to walk inside the structure.

Further it can be seen how the different equipment are fitted inside the structure of the site. It can be seen that there is a generator, 701, and a fuel tank, 401, fitted inside which gives power to the site. This is especially important since remote locations might not have the possibility to connect to an ordinary power grid.

It can also be seen that there are outdoor units, 402, in the form cabinets housing the different electronics needed for operating the site.

Usually the mast or the tower, 501, are fitted to the primary foundation and the e.g. tank, 401, generator, 701, and outdoor units, 402, are mounted to the secondary foundation, 201. Figure 8 gives a top view of the same site as figure 7 and it can be seen here that there is an access ramp in connection with the site and this can be made out of any material either gravel or even concrete.

Further the boundary wall, 301, is resting on the main beam structure, 101, and it is made out of concrete blocks. Further the ground the structure is resting on can be made out of 100 - 150 mm of thick fine gravel or in case of a more permanent structure it is made out of a light concrete bed.

In figure 9 and 10 it is possible to see an embodiment of the metal rods or wall bolts, 902, and how they are used for securing the wall, 301 , to the main girders, 101. The wall bolts, 902, are first connected to the girders, 101, e.g. by securing them to the girders, 101, by using a nut and a spacer. The bolt, 902, has a threaded portion, 903, in one end.

Further the blocks, 1004, are thread down, through holes in the blocks, 1004, on the wall bolts, 902, and when all the blocks, 1004, are in place a steel galvanized head, 901, is welded to the top of the bolt, 902.

Further the blocks, 1004, are fitted with one or more knobs on top that fits together with matching grooves underneath to make it easier to stack the blocks on top of each other in the right way and to stabilize the structure.

In figure 1 1 it can be seen a side view of a finished site, here it can be seen that in the top of the tower, 501 , there are placed 6 GSM antennas and that the tower, 501, is made out of reime which makes the structure very durable and strong and further it makes it very light weight compared to the height and the size of the antenna. In fact it is so light weight that the entire tower, 501, can be put together without any help from heavy machinery. Figure 12 gives a close up side view of a finished site and it can be seen how the different equipment are fitted compared to each other.

It is to be understood that the site depicted in these figures are only one embodiment of the invention and it is obvious for a person skilled in the art that the combination of equipment and the placing of this equipment or even the materials used can vary. The figures and the examples given here should therefore not be interpreted restrictive for the invention.