The industry must leverage the right standards and technologies to provide mobile-TV services on the go, deep inside buildings, and to millions of people at the same time.
Television and cellular phones are among the most popular consumer-electronic products in history. As a result, putting the two together should result in the ultimate killer wireless application. Numerous carriers and technology companies have been working on the rollout of mobile TV for some years now. Some services have been launched, albeit in a limited area and to only a targeted audience. For broader adoption, carriers need the right combination of infrastructure, handsets, content, and supporting technologies. In these early days of mobile TV, the right combination of technologies and investment is key to delivering services at a price point that users will accept.
Currently, the delivery of mobile TV is handled by either a two-way cellular network or a one-way dedicated broadcast network. Four main standards are in play to make such delivery happen (see "Four Standards Currently Propel Mobile TV," p. 36). For now, however, some industry experts believe that the easiest and most efficient way to speed the rollout of mobile TV is to use existing third-generation (3G) cellular networks. An example of such an approach is MobiTV (www.mobitv.com), which streams video channels over a carrier's cellular network. On most US carrier networks, MobiTV is now available for a number of Treo smart phones. According to the company, users also can watch Live TV anywhere in the US as long as they have a WiFi connection and either the Palm T/X or LifeDrive personal digital assistant (PDA).
The MediaFLO technology from QUALCOMM, Inc. (www.qualcomm.com) complements existing 3G infrastructure without using any of its much-needed capacity. Some people are looking at this technology with speculation, due to the fact that it is proprietary and the Digital Video Broadcast-Handheld (DVB-H) standard is gaining increasing acceptance across the globe. Yet MediaFLO continues to make impressive strides. At Mobile World Congress last month in Barcelona, Spain, QUALCOMM showcased its 8-MHz international mobile-broadcast platform throughout the Fira de Barcelona on European Channel 50. It featured 30 channels of TV and radio programming; IP datacasting applications for sports, news, and weather; and Clipcasting media and interactive services. The MediaFLO demonstrations were conducted in collaboration with Abertis, a Spain-based telecommunications-infrastructure management company along with a number of content and application providers.
Of the mobile-TV services that have been launched, the majority leverage unicast on the two-way cellular networks that are already in place. Content is therefore transmitted individually from one source to one destination. In contrast, a broadcast approach delivers the same content to many mobile handsets in only one transmission. Obviously, a hybrid unicastbroadcast approach is ideal, as it would provide subscribers with viewing choices while making the delivery of popular programs as efficient as possible.
Multimedia broadcast/multicast service (MBMS) is a packet-based broadcast service for mobile communication networks. It allows a single broadcasted frequency to carry multiple channels of content. TD-MBMS was created as an easy and fast-deployment mobilemultimedia solution for MBMS on TDSCDMA networks, as it requires relatively small changes to the underlying 3GPP standard. That standard should enable carriers to deploy these multimedia services with a comparatively low network-deployment cost.
This past fall, Zhongxing Telecommunication Equipment Co. Ltd.'s R&D Centre in Shanghai, China demonstrated TD-MBMS network services using Spreadtrum Communications' (www.spreadtrum.com) TD-SCDMA/GSM/ GPRS dual-mode chipset solution. This demonstration showed that TD-MBMS is technically feasible on the TD-SCDMA network built using ZTE's equipment. With the adoption of Spreadtrum's SC8800D TD-SCDMA/GSM/GPRS dual-mode chip and platform, TD-MBMS also could be applied to mobile phones.
Last month, Orange (www.orange.co.uk) and T-Mobile UK (www.t-mobile.co.uk) announced that they intend to pilot a mobile-TV and multimedia broadcast service in London using NextWave Wireless' (www.nextwave.com) UMTS MBMS-based TDtv solution. The pilot, which is scheduled for the second half of this year, will target people living or working in West London. Its goal is to demonstrate how the cost of providing high-quality, mass-market mobile-TV and multimedia broadcast services can be reduced when mobile operators share unpaired 3G spectrum and a standardsbased TDtv broadcast network.
During the six-month pilot, Orange and T-Mobile UK customers will use TDtv-enabled WCDMA handsets to receive up to 24 high-resolution television channels and 10 digital radio stations at a far lower delivery cost per channel than previously possible. By providing more channels with higher picture quality that are fully integrated with existing multimedia services, the pilot service is expected to conclusively prove customer demand for mobile-broadcast-TV and radio services. Mobile network operators in Europe and the Asia Pacific that own unpaired UMTS spectrum will be invited to participate in the pilot as observers. The same invitation will be extended to handset manufacturers that can make TDtv a standard feature in their devices.
TDtv operates in the universalunpaired 3G spectrum bands that are available across Europe and Asia at 1900 and 2010 MHz. It enables UMTS operators to utilize their existing timedivision- duplexing (TDD) spectrum to offer subscribers mobile-TV and multimedia packages without impacting their 3G voice and data services, which use universal-paired or frequencydivision- duplexing (FDD) 3G spectrum. The technology supports network sharing to further reduce deployment and operational costs. Last year, Vodafone, Telefonica, Orange, 3UK, and IPWireless (now part of NextWave Wireless) announced successful results from a technical trial of TDtv in Bristol. The trial demonstrated TDtv's ability to reliably deliver a large number of highquality channels in 5 MHz of TDD spectrum with coverage comparable to WCDMA, but with far fewer cell sites. It also showed the viability of dual-mode TDtv/WCDMA handsets as well as the ability of the technology to support full mobility at vehicular speeds.
The Orange and T-Mobile UK pilot will be powered by a mobile broadcast solution developed by NextWave Wireless. It will include the TDtv network infrastructure as well as a TDtv Device Integration Pack. According to the company, this chipset and software package enables handset vendors to quickly add TDtv to any multimedia-enabled WCDMA handset. In addition, NextWave's Packet Video (PV) subsidiary will provide a complete Electronics Programming Guide that will integrate the TDtv service with the operators' existing 3G services.
Many of these pilots rely on existing 3G handsets. As mobile TV becomes a standard application for future handsets, however, tougher and more specific requirements will have to be met. According to Dino Bekis, director of new business initiatives for Broadcom's (www.broadcom.com) Wireless Connectivity Group, "The handsets must deliver a combination of capabilities to support the growth of mobile-digital-TV services. Superior radio performance for deep indoor reception is key to the user experience. Extended battery life is critical for both carriersfor maintaining a service revenue streamand for users to have access to their other phone services in parallel. Additionally, users demand compact and elegant form-factor handset designs, which require very small footprint solutions to implement mobile digital TV."
To address the needs for better indoor coverage and low power consumption in a small form factor, Broadcom is taking a semiconductor approach. The company just announced a 65-nm single-chip receiver that supports the Digital Video Broadcast-Terrestrial (DVB-T) and Digital Video Broadcast- Handheld (DVB-H) standards. Specifically, the BCM2940 mobile-TV receiver is a monolithic, single-chip solution that integrates a dual-mode demodulator and tuner (Fig. 1). The BCM2940 vows to reduce power consumption by up to 40 percent and footprint requirements by up to 30 percent from current handset-design budgets. In addition, the chip's advanced tuner and demodulator design allows for improved reception both indoors and in high-speed environments.
The BCM2940 receiver promises to exceed IEC 62002 (MBRAI) specifications for mobile video applications. It boasts signal reception of -98 dBm sensitivity in DVB-T mode (QEF, QPSK-1/2) for all UHF/VHF channels and a noise figure of less than 3 dB for all bands. To provide extended battery life, the BCM2940 features 160 mW power consumption (typical conditions)209 mW with significant margin over MBRAI specifications (DVB-T mode). In DVB-H mode, it flaunts a low between time-slice power of under 0.8 mW.
A system-on-a-chip (SoC) approach also is at the heart of Analog Devices' (www.analog.com) mobile-TV receivers, which target the Terrestrial Digital Multimedia Broadcasting (T-DMB), Digital Audio Broadcasting (DAB), and frequencymodulation (FM) standards for the Korean, Chinese, and European mobile-broadcast markets. These receivers combine an RF tuner and demodulator on a single chip. The ADMTV315 is a front-end receiver for T-DMB/DAB/FM mobile-TV applications. It operates at only 100 mW (Band- III) and ~110 mW (L-band). By eliminating the need for an external low-noise amplifier (LNA) while minimizing the use of passive components, the ADMTV315 vows to reduce both board footprint and bill-of-material (BOM) costs. In addition, the chip provides full digital automatic gain control (AGC) with no need for external pulse-width-modulation RC filter and tuning.
For its part, the ADMTV316 is a dual-channel, frontend receiver. For handset designers who want to design in picture-in-picture (PIP) and Transport-Protocol-Experts- Group (TPEG) functions, this receiver enables simultaneous access to real-time traffic data and TPEG while watching TV. It also makes it possible to develop dual-channel mobile-TV applications with one 9-x-9-mm chip. Conventional solutions would require multiple chips.
Long-term evolution (LTE)the fourth-generation (4G) telecommunications standardsclearly holds great promise for mobile multimedia delivery in terms of both infrastructure and mobile handheld devices. NXP Semiconductors (www.nxp.com), for example, recently demonstrated a programmable LTE modem (Fig. 2). This LTE/HSPA/UMTS/ EDGE/GPRS/GSM multimode baseband platform forms the basis of a softwaredefined- radio (SDR) system solution. Powered by NXP's Embedded Vector Processor (EVP) digital-signal-processing (DSP) core, the solution is capable of achieving data transfer rates of 150 Mb downlink and 50 Mb uplink. It also supports multimode capability to cope with evolving mobile standards.
LTE promises customers an enhanced user experience as next-generation devices deliver ultra-fast Internet browsing, streaming video services, multi-player gaming, and even full-length HDTV films. Although the specifications for LTE are still being finalized, NXP was already able to implement the preliminary specifications. Thanks to the implementation of the highly parallel EVP, the company can update the multimode baseband as the standard evolves. That EVP provides the computational resources for both multiple-input multiple- output (MIMO) and orthogonal-frequency- division-multiplexing (OFDM) modem functionality.
With so many pilots and some mobile- TV services already available, the industry is clearly on its way to offering this service on a grander scale. Many regions have decided upon a standard, which is the first step. Now, it is a matter of deciding what technologies will best work in conjunction with existing infrastructure. The imminent approach of 4G and broader-scale mobile TV and other multimedia services will eventually translate into a need for new infrastructure. For now, however, the goal is not to incur those costs all at once. After all, the work of the carriers, handset makers, and other technology developers only makes this service available. If that step is not accomplished at the right price point, mobile TV will not be offered at a price that makes consumers biteno matter how tempting it may be to watch their favorite shows on the go.