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Mobile communications and Internet based computer communications are the two fastest growing
areas of communications indicating an enormous business potential in the intersection of these
two domains. Since the introduction of cellular networks, wireless communications have focused
on speech only, while mobile data has played a minor role. This paradigm is likely to change
drastically in the near future. A new phenomenon, reflected by a nomadic lifestyle, is spreading all
over the industrialized countries. Clear evidence of this is discernible particularly in Japan and
Scandinavia. Nomadic lifestyle suggests that we are now at the advent of a new era of mobile
communications, which will be fueled by rapid evolution of key technologies such as mobile
computing, low-power consuming RISC and signal processor technologies, wireless channel
aggregation, wireless packet data, and Internet based multimedia communications.
The current trend of network evolution implies that the Internet will serve as a core for future
service provision, whereas traditional telecommunication networks offer access paths to those
services. Internet telephony reflects the beginning of a new communication era, which is characterized
by running real-time applications over Internet/Intranet based computer communication
infrastructure. We can envision that soon they not only contain speech, but data, graphics and
video as well. It is obvious that also the nomadic users will require access to these services and
applications as they gain more popularity in the landline environments. Moreover, new wireless
Web applications are likely to emerge with no wireline counterpart.
Evolution of wireless communications will be driven by the rapidly growing Chinese market,
which is expected to be the largest one by year 2000. By its nature, this market is likely to
leverage new digital technologies, which enable low cost terminals, higher bandwidths, and
cheaper call rates. The downside of this technology is its limited coverage and vehicular operation
at low-velocities only. Industrialized countries will also benefit from this evolution, since they
share a growing need for high speed, low delay asymmetric wireless data access to the Internet.
Low-tier micro-cell technology is capable of addressing best those needs of current terrestrial
wireless systems. The problem of limited coverage will be solved with multi-mode transceivers.
We have characterized in this investigation the new paradigm of mobile communications by
introducing a virtual model of personal multimedia communication space. On the basis of our
model, we have reviewed the impact of international standards on low bit-rate real-time multimedia
communications with some basic considerations of system architectures.
The feasibility of wireless Internet telephony over packet radio networks has been assessed. It
seems that the latency problem faced also in the wireline IP environments becomes overwhelming.
Moreover, wireless packet switched IP environments lack the cost incentive of the Internet. Endusers
are not likely to accept such wireless Internet telephony. Full-fledged voice-over-IP in
wireless networks is not feasible before low cost, low latency wireless packet access is available.
The need for such a service is an open question. Therefore, usability experiments are needed.
Multimedia applications are likely to play much more important role as a driving force for voiceover-
IP in wireless environments than in the fixed network. In a limited scale and in the medium
term, Web browsing with concurrent voice communication may become available, based on multilink
packet radio extensions of current digital cellular networks. |
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