Fixed-Access Wireless Access Systems

In common with wide area mobility networks, fixed-access wireless networks need to
be able to handle bursty bandwidth. This means the same issues of protocol performance
apply, albeit without the added complication of a mobility management overlay.
Users in a fixed-access network, by definition, stay in the same place. Fixed-access
networks can either be deployed as a number of dumb fat pipes or a larger number of
smart thin pipes—for example, using ATM.
Fixed point-to-point hardware is already widely deployed in existing terrestrial cellular
networks, predominantly 38 GHz point-to-point links between cell sites or
between cell sites and BSC or RNC or MSC switch nodes. Similar hardware is used to
provide links in digital TV transmission and TV distribution networks. Theoretically
this should deliver some economics of scale and common deployment experience.

In practice, there are so many different flavors of different hardware at different frequencies
that this has tended to prevent widespread deployment of fixed-access radio
as a substitute for wireline access. If a vendor has too many products to choose from,
he or she often makes a choice not to choose any of them. The problem has been compounded
by a confused and disparate fixed-access wireless standards-making process.
The fragmentation of the market in terms of technology and the fact that so many
different frequencies have been allocated in so many different countries make it hard
to realize economy of sale when manufacturing radio transceivers. RF components are
still quite expensive above 10 GHz, and it is difficult to achieve consistent RF performance
between units leaving a production line.
In parallel, wireline access performance is improving (with techniques like VDSL),
and wireline access costs are reducing. Wireline networks have often already been fully
amortized over many years.
The fact that fixed wireless access systems are still, even if only to a small degree,
weather dependent also militates against their widespread adoption. 374