A Network within a Network within a Network

In a perfect world, devices would roam seamlessly between Bluetooth, IEEE, picocells,
microcells, and macrocells (see Figure 15.2). Picocells, microcells, and macrocells work
together very well but use substantial signaling bandwidth to achieve the happy state
of effective communication. Getting cellular handsets coordinated to work with wireless
LANs and Bluetooth is technically difficult and probably impossible in terms of
standards integration, because too many different vendor interests are involved. This
is the concept of data clouds—the ability to log on seamlessly to a public access or private
access wireless LAN and upload or download or exchange high-quality audio and
video, either using IEEE802 or Bluetooth.
In Europe and Asia, Bluetooth devices are being added to cellular handsets, but,
with the exception of earbud applications and PDA synchronization, they are not
widely used. Public access wireless LANs have not achieved widespread market adoption
to date in European and Asian markets because of technical constraints (power
limitations and problems with co-existence with Bluetooth) and regulatory reasons.
Cellular operators are only marginally interested, since they already have saturated
coverage and adequate capability in hot spot areas and will greatly add to that capacity
with the introduction of Node B 5 MHz transceivers.

In the United States, public access wireless LAN networks may achieve a measure
more success, but it is difficult to imagine wireless LANs becoming pervasive on a
worldwide basis for technical, commercial, and political reasons. 367