How technology cycles can drive PDA adoption

Carl Zetie and Ken Smiley

Fundamental limitations in current PDA technology rule out some things we’d

like to do. How fast can we expect things to improve?

The technology that makes up a complete mobile or wireless solution consists

of a complex stack of hardware, software and infrastructure components, each of

which is on its own cycle for improvements. Because personal digital assistants

(PDAs) are often pushing the limits of size, weight and power, these limits are

often more significant to PDA deployments than they are to typical desktop or

laptop-based applications. Some of the key cycle times are as follows:

• Minor software upgrades: Every six months to one year. These provide
  
  incremental improvements in capability, perhaps adding support for new
  
  markup languages or new hardware interfaces such as adding SD support. Like
  
  PCs, PDAs may increasingly get virus definition upgrades on a near-daily
  
  basis.
  
  
• Major software/operating system upgrade: Every two to four years. These
  
  provide significant improvements. For example, Pocket PC 2002 added greatly
  improved security and mandatory upgradeable flash memory over previous
  
  versions, and PalmOS 5.0 will provide greatly enhanced multitasking. Upgrade
  
  cycles have accelerated recently and may come as fast as every 18 months in
  
  the future. Note, however, that operating system upgrades are increasingly
  
  closely tied to hardware upgrades as the two are become increasingly
  
  intertwined.
  
  
  
• Memory (RAM) size: Doubling every year. Fundamental improvements in memory
  
  technology are on the same 18-month to two-year cycle as for PCs, but the
  memory available in PDAs is also tied to the cost of memory, which has a
  
  cycle all its own that goes up as well as down. On average, the
  
  "typical" memory in PDAs has been more than doubling every year,
  
  with the maximum available memory growing slightly more slowly.
  
  
  
• Processor speed: Incremental increases every three to six months.
  
  Discontinuous increases every two to four years. Two different cycles affect
  processor speed. While a PDA stays within a single processor family,
  
  improvements come in comparatively small increments, and the rate of
  
  increase depends on whether faster processors are available for immediate
  
  adoption and whether faster versions can be added. For example, during the
  
  past three to four years, Palm PDAs have moved from 16Mhz Motorola
  
  Dragonball 68K CPUs through the 33Mhz processors found in most current
  
  devices to the 66Mhz processors found in the fastest devices. Meanwhile,
  
  Pocket PC-based devices have standardized on the StrongARM processor running
  
  at 206Mhz and no longer support MIPS or SH3 processors. More dramatic
  
  increases can occur when a PDA moves from one technology to another, for
  
  example Palm’s move from Dragonball 68K to ARM in the forthcoming PalmOS
  
  5. Such discontinuous increases are typically tied to the major operating
  
  system upgrade cycle. Note, however, that some devices may choose not to
  
  exploit the full speed of a given processor in order to reduce power
  
  requirements and improve battery life. Also, without supporting changes in
  
  the operating system, a new processor alone may not provide a performance
  
  boost, as has befallen the new 400Mhz XScale processors in the latest
  
  generation Pocket PC devices. Consequently, these two cycles need to be
  
  considered jointly.
  
  
  
• Mass storage: In the past, the rate of increase of technologies such as
  
  SmartMedia or Compact Flash Memory has been roughly to double every year.
  With Microdrives from vendors such as IBM now offering 5GB or more of data
  
  in a Compact Flash format, and solid state Compact Flash memory offering
  
  1GB, availability of mass storage should very rarely be a limiting
  
  technology today. Toshiba has a 10GB drive in PCMCIA format, expected to go
  
  to 20GB next year. SD memory continues to trail behind other formats in
  
  size, currently topping out at 128MB; however, it should make up the
  
  difference following a slightly accelerated schedule as compared to other
  
  formats.
  
  
  
• Network bandwidth: Ten-fold increase every three to five years. Bandwidth
  
  on the cellular networks has almost the slowest and the most discontinuous
  change cycle. Data bandwidth is tied to the generational network upgrades of
  
  the wireless carriers, and these are massive infrastructural changes that
  
  take place over three- to five-year periods. Under 2G digital mobile
  
  networks, 14.4Kbps was a normal maximum for mobile data, perhaps achieving
  
  28.8kbps equivalent with software compression. Under the 2.5G networks
  
  currently being rolled out (CDMA 1xRTT and GSM/GPRS), expect 25Kbps to
  
  70Kbps average performance without compression, increasing gradually to
  
  80Kbps, potentially peaking at 150Kbps. Future 3G networks promise the
  
  possibility of up to 2Mbps when stationary, less when moving, but will not
  
  be widely available until 2005. Some intermediate relief may be offered by
  
  the growth of "hot spots" along with seamless LAN-to-WAN roaming,
  
  but such technologies are geographically very limited (see Planning
  
  Assumption, Wireless LAN to WAN: Solutions Beginning to Appear, Stan Schatt).
  
  
  
• Battery life: Fundamental power technology has changed very slowly
  
  compared to these other technologies, although significant incremental
  improvements in size, weight and life have been driven in recent years by
  
  demands of the cell phone industry, among others. The arrival of dramatic
  
  improvements in power technology is unpredictable, but incremental
  
  improvements in battery life in the near term will come more predictably
  
  from better components, including more efficient displays, CPUs with better
  
  power management as epitomized by the Transmeta Crusoe and Intel XScale, and
  
  smarter software that can manage the power consumption of the system
  
  according to need. Supplemental power sources are becoming increasingly
  
  available as the number of mobile devices in use drives demand, including
  
  user-swappable batteries, power sockets on airplanes, hand-wound and solar
  
  chargers, etc. Giga’s Power 2002 conference will discuss these topics in
  
  detail.
  

By identifying the fundamental limitations that make a particular deployment

infeasible today, and understanding the cycle time associated with that

technology, you can better understand the trade-off involved between

compromising with today’s technology and waiting for something better to

arrive. Given these independent cycles, Giga advises re-evaluating the

suitability of the PDA as a platform at least once a year if it has been deemed

to be inadequate in the past.

(Contributing Analysts: Rob Enderle and Brownlee Thomas.)