The future of mobile network, from LTE to HSPA+
To meet the strong demand for energy required from smartphones and other mobile devices, telephone companies are engaged in both the construction of new facilities and implementation of existing networks.
The new networks are divided into two main technologies: WiMAX and Long TermEvolution (LTE). The two systems use similar approaches to supply the availability of bandwidth than the current one. A method called OFDM (Orthogonal frequency-division multiplexing) allows a base station to split a portion of spectrum in sub-channels. The signal strength of the subchannels and the number of channels allocated to different devices can be changed. OFDM allows highspeed data transmission, even far away from the base station, and fits well with all types of radio interference present in urban areas, where the signals reflected on the walls produce confusing echoes.
Both LTE and WiMax are based on the MIMO method (multiple input, multiple output). It uses multiple antennas to create a single wireless connection. MIMO can package the data with a higher density in the wireless spectrum available than a system with a single antenna, which consumes the same amount of energy.
WiMax has arrived on the market two years before LTE; it offers a theoretical maximum download speed of 144 megabits per second compared to the 360 of LTE (the United States a standard residential broadband connection is around 10 megabits per second ). LTE seems to have an overwhelming speed advantage, but in reality wireless mobile companies are far from reaching that performance of both technologies. In the U.S., Sprint’s WiMax network reach speeds between 3 and 6 megabits per second, while Verizon’s LTE network is between 5 and 12 megabits per second.
Although Sprint and Verizon have them labeled as 4G, these services do not actually meet the performance criteria that the ITU (International Telecommunication Union) has called officially for 4G services. But the latest version of WiMax and LTE are trying to meet these standards, guaranteeing download speed up to 1,000 megabits per second or even higher.
Although WiMax has been developed more quickly (the first large-scale deployment dates back to 2008) most operators in the U.S., Europe and Japan are using LTE for next-generation wireless networks. The main reason is that they assume that LTE network is technically easier to integrate with their existing structures.
But some suppliers, such as T-Mobile in the United States to upgrade their existing 3G networks, they prefer a system called HSPA+. T-Mobile claims that HSPA+ enables peak download speeds of 21 megabits per second, enough to compete with next-generation networks, at least for now.
At present all the network operators are committed to enhancing the capacity and flexibility of their 3G networks. Over the next four years, when the next generation systems will be developed and 3G chips will become cheap enough to make their appearance in a wide range of consumer products, these systems will attract more subscribers of the LTE network.
The biggest obstacle to the improvement of these systems comes from the wired network, not from the wireless. The cell towers and base stations must be connected to the same network hub. These links from one point to another, which typically use copper telephone wires or special connections or microwave, in recent years have become real bottleneck, forcing operators to adopt the more expensive fiber connections.
About 95 percent of the new Verizon LTE data network will be over fiber. But dig into the streets to lay fiber optic cable in densely populated areas can be expensive. For this reason, AT&T is committed to improving its 3G service in New York, which must withstand the impact of thousands of iPhone users.
Filed Under 3g, mobile network, wimax | Comments Off