4G networks for autobahns

The modulation of the laser beam by the 4G ultra-wideband multimedia signals has arisen from the need to deliver these signals to the base stations of the mobile network using ultra-wideband fiber optic distribution networks.

            The LTE technology (Long-Term Evolution) of the international consortium 3GPP is expected to become soon the leading technology in mobile networks.

LTE networks have already been deployed in many countries. For example, a scientific review of literature on the subject shows that German carmakers are already equipping their vehicles with LTE access points securing the data rate of 23 to 70 Mbit/s. In addition, Chinese mobile operator China Mobile has launched TD-LTE network along the railway lines of high-speed express trains. Thus, on the line Shanghai - Hangzhou 60 km long 18 base stations have been fitted. The network can transmit data at a rate of 15 Mbit/s while the speed of mobile subscribers levels at 300 km/s.

An analysis has shown that a further increase in the data rate in mobile communication networks is limited by the available radio bandwidth and the principles embedded in the way subscribers communicate with the base stations using the conventional handover procedure.

 In order to ensure an acceptable quality of service for highly mobile subscribers a variety of solutions are being designed to simplify the handover procedure, namely, the use of "phantom" and "cloud" cells. Frequent recourse to the handover procedures increases the probability of packet loss and causes rapid discharge of the battery in mobile terminals.

 The literature review has crystallized the unfulfilled demand on the part of the public to organize a high-quality mobile communications, which provide 4G services for the subscribers moving at a high speed on the motorway or in express trains.

To sum up: the demand does exist; the problem is there to be solved. All these facts point out that the topic is highly relevant.

One should not also omit the fact that along with the speed increase of the subscribers up to 200 ÷ 250 km/h on autobahns and up to 350 km/h for railway express trains there are growing requirements to increase network capacity up to 2 thousands of subscribers. If each of them is served with a channel providing the data rate of 12 Mbit /s, the total instantaneous bandwidth ought to be 24 Gbit/s. When one uses QAM64 modulation (Mk =6) required working frequency band for a distribution network delivering signals with 4G services reaches Δƒ = 4GHz.
           Today, there is no in the world of such a distribution network of synchronized delivery for each base station signals of all subscribers, nor a technology for generating a laser beam, modulated by the two thousand signals, each with the rate of transmission in order of 12 Mbit /s.

Thus, taking into account all above scientific work entitled "Modulation of the laser beam with ultra-wideband multimedia 4G signals» by Alexander Golik L, which has been presented before the extended panel of the Radio technologies Department of the University is highly topical.

Sayko, 249-25-04