The present development aims to solve an important shortcoming, very often in marginal areas, with respect to telephone communication for those inhabitants who, due to their geographical location, do not receive fixed telephone service, nor do they receive mobile cellular telephone providers. in optimal conditions.
It is known that in rural areas, geographically located in areas to which the physical lines corresponding to the fixed telephony provider companies do not reach, it is possible that they can access a mobile cell phone service, given their possible proximity or reach to a certain existing cell in the vicinity. But there are inhabitants, fundamentally in areas similar to the mountainous area, western Patagonia Argentina, or the entire mountain range or mountainous area itself, in which conditions are totally adverse and communication is almost impossible.
Many inhabitants of these regions consult us, stating that they have been able to determine that on the top of a hill near their property, using a cell phone lent by a friend, they have managed to communicate, but that great "communicating hill" is located about 3 or 4 thousand meters from your home. Then the need arises of how to carry that blessed cellular signal to your house enclosed between hills. But of course, once there is such a possibility, the question is: can we use fax ?. But the thing does not stop there, and then it comes: can we use the Internet?.-
Project Origin
The origin of the project is based on providing an effective and relatively inexpensive solution with respect to what could eventually be solved in other cases with a single-channel system with an intermediate repeater or in the worst case with a digital microwave link, which also it would need to be repeated perhaps more than once, of which the costs would rise considerably. Not to mention a satellite team. The present system is cheaper than a single channel with an intermediate repeater. It offers the possibility of using fax, Internet, e-mail and can also be incorporated into a telephone exchange with its respective interns, as if it were a conventional urban line.-
Communication Need
It is obviously proven that nowadays the need for people to communicate is more and more necessary every day. Either for business, for possible emergencies or simply to maintain regular contact with a family member or friend. In short, do not feel isolated or alone. A simple rural inhabitant must be able to maintain communication with his peers in another place even without having to leave his home, which is also far away. There are rural enterprises of a commercial type that need to buy and sell and even more so if it is important establishments with high productive capacity with the usual increase in personnel inhabiting the place. In summary, there should be no limitation for an inhabitant of a rural area to be reduced in communications, with respect to his fellow city-dweller.-
Internet / E-Mail At Hand
No one can be oblivious to the fact that at present, in order to develop any activity, whatever it may be, the most imperative is information. The need to be informed about what is happening in the world in any field. Internet is the way that offers us the greatest possibilities at the lowest cost. And what to say about being able to send and receive messages by email, which due to its low cost, made us put aside the fax while we can, although there are cases in which the latter is the only option. The present system allows us, always according to the possible limitations of the elements we have, including mobile cell phone cells, to send and receive faxes at its maximum speed (9,600 KBPS) and to work on the Internet and email at least 14,400 KBPS,Not a negligible thing for the situation of conditions that we are proposing.-
Take advantage of existing resources
One of the most important factors to highlight in this development is the fact that it was developed taking into account the means available to the market, easy to obtain, simple to install and fundamentally cheaper than any other similar system.
We are going to present a situation that is one of the most common for the implementation of this system:
Our friend who lives in a rural area, in a mountain area and perhaps just 30 km away from the nearest city. On the way you enter your home, the physical telephone wiring does not pass since fixed telephone companies are logically not interested in investing in wiring areas where they can only provide their service to very few clients. In addition, the house that our friend lives in is located in a valley, surrounded by hills that are not very high perhaps but that prevent any cellular signal from being received from it. It is known that in mountainous areas, cell phone providers obtain authorization to install their important equipment and antennas on the top of some mountains, which do not necessarily have to be so close to a populated center.This location allows them to go further without the need to invest in tall metal structures, such as if they were at ground level. As we know, cell phones need the antennas to "be seen" to be able to carry out a communication, consequently as we said before, our friend has hills around him that do not allow us to see the cellular antennas, but if we go up to a nearby hill to your home, we find that we have an excellent cellular signal even with a small pocket phone, but we go back a few meters back towards the house and everything dissolves.Consequently, as we said before, our friend has hills around him that do not allow us to see the cellular antennas, but if we go up to a hill near his home, we find that we have an excellent cellular signal even with a small pocket phone, but we go back a few a few meters back towards the house and everything dissolves us.-Consequently, as we said before, our friend has hills around him that do not allow us to see the cellular antennas, but if we go up to a hill near his home, we find that we have an excellent cellular signal even with a small pocket phone, but we go back a few a few meters back towards the house and everything dissolves us.-
Now, we know that on a hill near the house we fear a good cellular signal, but we also know that to achieve this we had to travel upward perhaps 10 km. How do we lower the signal from a cellular device to the house? Carrying out a cable laying either overhead or underground is extremely difficult for us since the ground in question is totally stony. The distance is long. The cost is high. We are aware of single-channel telephone equipment that allows us to transport at least one telephone pair wirelessly over a considerable distance depending on its characteristics. There are different powers and operating frequencies for which we choose the most appropriate for our case. With this single channel we already have a link between the house and the hill. In the house we put a simple telephone set.On the hill, what do we do if we only have a cell phone? There are so-called cellular interfaces. What do they do? How do they work?. What are they for?. The so-called cellular interface allows us to link a cell phone with a conventional telephone or any type of telephone device that needs a fixed-type analog telephone line. In other words, it is a device that is connected on the one hand to the cell phone and on the other hand to the central side of the single channel. The aforementioned interface can "make you believe" a conventional telephone that it is connected to a common physical line and even generates its own tone of invitation to dial, which we all know cell phones do not do. If after 6 seconds we do not press another number key,she determines that the desired sequence of numbers has been completed and therefore indicates to the cellular equipment the "SEND" command and the communication follows its normal course. It also generates the corresponding chime current of about 60 VAC when it receives a call and even produces a busy tone when eventually, when attempting a call, there is no cellular signal or power supply to the equipment.
Personal Experiences and Theory of Operation
The particular experiences, which have not been few and have led me to adopt high quality and renowned products such as the Motorola Carry Phone TX-400 3 Watt power cell phone and its corresponding cell phone interface of the same brand, Motorola S1936D Catalog. For this equipment, an external yagui-type antenna with 10 elements and 12 dB gain is used, having also used a dihedral antenna with similar gain in some cases. The single channel must be of optimum quality to ensure correct data transmission when using fax or PC. The interface links the cellular equipment with the central side single channel, obtaining power from the same equipment. It has a whip with a male RJ-45 connector which is plugged into the cellular equipment in the place intended for the handset. On the other hand,a female of the same type when the need to keep the handset connected. And finally an RJ-11 female to plug in the 1-pair line cord whose other end is inserted into the single-channel line input.
Schematic diagram
Schematic diagram of a telephone communication project
Simple cost analysis.
Of all the existing possibilities, the system described above turns out to be the most economical and reliable.
- Microwave link: Very high cost and it is not justified under any point of view for a single telephone
line.- - Satellite telephony: Currently the equipment is somewhat cheaper, but the cost of calls, whether outgoing or incoming (paid of the caller), they are extremely high.-
- Single channel with single channel repeater: The cost of the equipment is exactly double the value of a single single channel. It is also necessary to have your own physical telephone line in the vicinity of a populated center.-
- Single channel with cellular repeater: The cost of equipment results from the value of the single channel equipment (about US $ 2,500 in Argentina for an excellent quality equipment) and The value of the cellular equipment plus its interface can amount to a value of about US $ 450 in Argentina.-
Author's conclusions.
In this case, the author of this informative work is the same one who developed the system, based on existing technology, for which an accessory bibliography on which it was based is not included since it does not exist, or failing that, this would be the first. I, the author, have managed to install up to 3 congruent parallel systems in a telephone exchange and whose antennas I have mounted in the same tower in places and to clients to which the impossibility of any other option to be communicated was generated. Everything is a matter of being able to find the necessary elements for a project to work. In this particular case, the following elements were taken into account for the present development:
- A good and competitive cell phone service in the area
- - A good cell phone equipment product like the Motorola Carry Phone TX-400. -
- An effective accessory complement to the aforementioned product, such as the Motorola S1936D interface.-
- A good quality single-channel telephone equipment to guarantee the best voice communication and data transmission.-
- All this must be complemented with accessory products of good prestige. By that I mean: antennas, coaxial cables, connectors, towers and a good electrical power system project, which deserves a separate chapter.
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