Rich data services require more signal power.

Cellular networks, originally dimensioned for voice communication, are being called upon to provide high-speed data communications and support a new era of 3G data services like video services, web access, full-featured email, MP3 sharing, and other rich data content use.  And this trend is expected to increase as wireless evolves from 3G to 4G and beyond. But today’s cellular networks are not capable of providing high speed data everywhere because these new, high-speed, heavy content data services require more signal power between the mobile and the cell tower.  Without more signal power, the effective size of the cell shrinks and thus service coverage is reduced.

To address this challenge, wireless carriers could install more cellular base stations, but this is a hugely expensive and time consuming effort.  A possibly more effective alternative is to increase the amount of power being transmitted in the network when and where it is needed. A cellular base station can reach the mobiles by transmitting stronger signals because they generally have ample power to spare, but today’s cell phones, data cards, wireless laptops, and other mobile wireless devices are often unable to reach the base stations due to limitations in their transmit power circuits.  These transmit circuits use components and architectures that either simply cannot produce the needed signal strength, or struggle to produce it and end up over-heating, distorting the signal, or using battery power unacceptably fast. So the mobile’s user is faced with no connection or a poor connection with slow data rates that includes shortened battery life and possibly an overheated phone or data card.

On top of this expansion of data services, there has been an increase in the use of cell phones, data cards and wireless laptops for 3G services indoors.   This increases the challenge outlined above since the loss of signal strength due to blockage from walls, ceilings, and surrounding buildings increases the need for signal power.  Here again, while the base station can make up for this lost signal strength, today’s mobiles hit a limit in their maximum transmit power and thus the chances for sub par coverage, slow data rates, or failed connection attempts increase even more.

Source: Derived from data in 3GPP document RP-030259.pdf

As an additional factor effecting these challenges, the movement by the wireless industry toward higher data rates in planned evolutionary technology (LTE, WiMAX, etc.) continuously increases the modulation complexity of the uplink signals, which increases the peak to average ratio (PAR) of the signal content.  Common power amplifiers (PAs) used in today’s transmit circuit must reliably process these higher PAR signals, but the PA can only do this by lowering its transmit power setting in order to pass the more complex modulation without distortion.  This power reduction accommodation is called “back-off” and is commonly used in most transmit circuits.  Thus, ironically, instead of increasing signal power to minimize the coverage issues outlined above, the mobiles actually decrease signal power.

Quantance can help address these challenges

By using Quantance technology, wireless carriers as well as wireless phone and data card providers can face the coverage, battery, and overheating challenges outlined above without impact to wireless network infrastructure and with seamless integration of technology into mobile wireless transmitter designs.  Simply stated, Quantance makes more signal power available from the mobile eliminating the need for back-off without requiring more battery power, and at the same time reduces the temperature of the PA in its hottest mode of operation.  To understand how, refer to the TECHNOLOGY section, and to understand in more detail how this will benefit the wireless industry across the value chain, refer to the BENEFITS section.

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