What will LTE look like?

What kind of end devices will be used on these LTE networks? One vision is a small LTE modem device that can plug into anything, such as a cell phone, a portable media player, a gaming device, or a computer. Plugged into a computer, the device acts as a global wireless local-area network (WLAN). In a portable media player, it could enable users to download a tremendous amount of content or watch streaming television shows. In a gaming device, it enables real-time, graphics-intensive multiplayer wireless gaming.

This new LTE modem would work in much the same way as a WLAN works today with a PC. The host, which is the cell phone or other portable device, receives data packets that can come from one of many sources, including the LTE modem. The LTE modem receives the signals, packetizes them, and sends the IP data packets into the host, and the host processes them. These packets could include DVB-H signals for broadcast television, WLAN for fixed broadband, or LTE signals for mobile broadband.

How not to melt a cell phone

Commercializing this technology will require some thought about the needs and wants of end users. End users are worried about power consumption, because they don’t want to lug around a big battery. They want small, portable devices with user interfaces that are easy to understand. Most of all, they want something that is affordable. That translates into several engineering problems. For example, an LTE device that consumes low power presents two main concerns.

First, you must transmit the data. Typically, the power amplifier uses more than 50% of the power in any mobile phone. Transmitting high-speed data requires a great deal more power. To retain small form factors, that current draw must be reduced using sophisticated engineering techniques such as dynamic voltage and frequency scaling.

Second, very high-speed signals require a lot of data processing. Today’s engines process tens of millions of instructions per second. But these new techniques will have to process several billion instructions per second at low power.

Small form factors require a large amount of integration. This is becoming increasingly important in modern devices that can contain an MP3 player, TV capability that requires a DVB-H or MediaFLO chip, games that require an applications processor, and connectivity options that can include Bluetooth, WLAN, and GPS. Yet despite all these added features, consumers still want to be able to slip their phone into their pocket.

An example solution

Freescale Semiconductor has developed one approach to the LTE challenge. At the 2008 Mobile World Congress in Barcelona, the company demonstrated streaming high-definition video over an LTE link with peak data rates of 182 Mbits/s downlink and 86 Mbits/s uplink. It’s working on several solutions to the technical challenges of mobile broadband, from the handset to the basestation.

For end devices, Freescale developed special ultra-efficient processor units that can handle the computationally intensive processing of LTE data flow at low power. A micro-coded engine for orthogonal frequency-division multiplexing (OFDM) provides the flexibility of a DSP and can handle the enormous instructions-per-second load required to process high-speed data.

Another micro-coded engine will handle multiple software interfaces to the media access control (MAC) layer, allowing the end user to multitask. For instance, you could watch streaming television and make a data call simultaneously.

For network operators, Freescale has solutions available through its ODM/EMS partners and third-party ecosystem. The Rapid System Development Platform is a comprehensive hardware and software reference package that enables OEMs to quickly plug together their own systems for evaluation and development. This modular, programmable basestation reference platform includes an industry-standard MicroTCA development chassis and processor boards and software for Layer 1 and Layer 2 development.

The long-term evolution of cellular technology has tremendous potential. Compelling services over fast networks will have profound effects on the way we do business and go about our daily lives. Although the technical challenges are many, complete solutions are in the works to pave the road to the broadband future.

Tom Deitrich is the senior vice president and general manager of cellular products at Freescale Semiconductor Inc. Tom has extensive experience in product management, research and development (R&D), supply chain management, and business development for wireless products. He has a bachelor’s degree in electrical and mechanical engineering from Widener University and a master’s degree in electronics engineering from the University of Pennsylvania. He also holds a master’s of business administration degree from Marquette University. He can be reached at B07142@freescale.com.

Related Articles:

1. Shining A Light On LTE
2. GSA Confirms 26 Operators Committed To LTE
3. Product Line Supports Complete LTE Infrastructure
4. HARQ Process Boosts LTE Communications
5. Agilent Announces New Test Solutions For Upcoming 3GPP LTE
6. Wireless Radio System Demonstrates 3GPP Capability