For a long time, it has been held that WiMAX has a definite and powerful
time-to-market advantage over LTE and LTE-Advanced networks. This is because of
WiMAX’s maturity as a technology, but also due to its higher readiness to be
deployed. On the other hand and despite the many commitments, LTE remains at
the trial stage largely.
Recent market reports, however, indicate thatWiMAX’s advantage may be
short-lived and that WiMAX, despite prospects of growth, will be eventually
eclipsed by LTE’s growth, which is projected to take an exponential at the time
of writing this article.
More generally speaking, both technologies share common facilitators and
inhibitors when it comes to deployment. The following discusses some of these
common aspects, including spectrum allocation, small cell concept, WiFi spread,
the backhaul bottleneck, and operator readiness for 4G investments.
Spectrum
Allocation...........................
Spectrum allocation and management, for example, have been observed to be
an impediment when it comes to deploying LTE networks, particularly in
Europe.This is especially the case given recent activating in auctioning
spectrums in the 700 to 1000MHz range, in addition to the relevant auctioning
policies and guidelines that have been set by the different regulators.
In the summer of 2011, the European Parliament meet to decide on the fate
the 800 MHz, and whether it was possible to harmonize its allocation for
broadband services. At that same time, UK’s Ofcom had decided to cap spectrum
purchases in the then upcoming auction for LTE spectrum, and fears from
monopoly in the then upcoming French auction had raised requests for a similar
policy. A highly relevant debate that is currently taking place is one that is
contemplating new models of spectrum allocations, management and trading.
At low frequencies, however, a lower number of base stations is required to
cover the same the area. Areas that have been underserved until now, such as
rural and suburbia, would therefore benefit greatly from such low frequency
allocations. This tradeoff between frequency and deployment costs, however,
should be viewed while minding capacity. To be noted however, high frequency
and short range coverage can be especially effective in providing high capacity
wireless links, especially when advanced antenna techniques, that is, MIMO, are
exploited.
Small
Cells.....................................
On the facilitation side, the “small cell” phenomena seem to be gaining
great popularity on both the operators’ and the users’ side. Both 3GPP and IEEE
have made extensive support for accommodating “small cells” that can be
deployed either as femtocells, relay stations or out-of-band WiFi cells to which
the IMTAdvanced users can be migrated to. Measures for inter-technology
handovers, mandated by IMT-Advanced requirements, means that users can migrate
their active connections to WiFi networks. Small cells benefit from the above
noted advantages, achieving high capacity gains by both reduced coverage and
limited subscriber access. In the case of WiFi networks, great cost savings are
made as WiFi nodes operate in the unlicensed ISM band.
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In addition to their other advantages, the economic advantages of relay
stations have been repeatedly demonstrated in various techno-economic
evaluations, and for both transparent and non-transparent relaying.
Such advantages have been demonstrated through different evaluation
scenarios, for example, rural, suburban and urban, and under different antenna
structures. It was found, for example, that relay stations can provide
substantial gains in rural deployments made under high frequency spectrum
allocations. Such deployments would naturally use non-transparent deployments
as the interest would be largely in expanding coverage. Meanwhile, relay
stations (mostly transparent) combined with the advanced antenna technique
prove more useful in denser deployments commonly made in suburban and urban
areas.
Offloading to femtocells and WiFi will reduce the traffic load on an
operator’s backhaul network. In the various femtocell offerings that have been
made in the market, operators may also gain increased revenues from fetmocells
through monthly fees, greater loyal and reduced churn. Certain studies,
however, have cautioned from generalizing cost reductions in all deployment
scenarios. For example, it is possible to such gains in areas where there is a
sparse macrocell deployment. The deployment of femtocells in these scenarios would
overcome the indoor coverage challenge, and offer enhanced service rates – all
at a much a reduced cost than increased macrocell deployments. Meanwhile, in
areas where there is already a reasonable macrocell density, the benefit of
femtocell deployment may be marginal.
The WiFi
Spread.........................................
Meanwhile, WiFi deployments are continuing a steadfast wide deployments and
at an international scale. It is now common to expect free or low-cost WiFi access
in nearly all possible venues. The technology’s low deployment cost, in
additional to minimal requirements of operational intervention, enable WiFi
access providers to deploy very large networks in short durations. Vendors such
as BelAir Networks, for example, continue to grow in their market share with
their focus on small cells including both WiFi and femtocells, but largely the
former. For example, BelAir offers Plug n’ play WiFi routers and femtocells
with Power Line Communications that can be fit in very short times on existing
power, diminishing infrastructure and rental costs for operators.
WiFi
deployments also continue to gain strong grounds in the enterprise. Such large-scale deployments of WiFi networks
open the possibilities of new business models. Through joint resource
managements, operators deploying mixed access technologies will be able to
manage the resources of the technologies in a joint manner, migrating users
from one technology to the other based on operational objectives. At the same
time, companies are now offering services that facilitate smooth
inter-technology handovers, exploiting the recent advances and standardizations
that have been made available.
The Backhaul
Bottleneck..................................
One notable impediment to the realization of the full capacities of
both IMTAdvanced technologies (WiMAX and
LTE) is the incapability of operator’s backhaul networks to cope with the
advances at the radio interfaces. Observations
that have been made from the onset of the race towards the IMT-Advanced
standardization still stand true today – that in terms of capabilities, both
IMT-Advanced technologies stand on equal footing in terms of general
performance and compliance to the overall ITU-R requirements.
However, as is
noted , many carriers are constrained by 1.5 Mbps (T1) backhaul, creating a
definite limit on network performance, regardless of capabilities of the chosen
radio interface. Existing technologies, including both packet microwave and
fiber optics, are more than capable of answering the project user demands for
IMT-Advanced. Investments decisions, however, have mostly been delayed by the
debate on the technical qualities of both access technologies.
Readiness for 4G.........................
A note should be made here on the reluctance of incumbent cellular
operators to invest in new infrastructures. Substantial investments were made
by these operators in 3G networks, both backhaul and infrastructures, which
partly justifies the delay as the full revenue potential of these networks is
yet to be realized.
It is hence that many operators around the world have sought government
support, especially through the most recent economic downturn. In many
countries, including the US, Canada, Europe, Australia and New Zealand,
economic surplus packages have dedicated funds to support expanded broadband
infrastructures, especially when it came to rural and sub urban areas. Such
funds, in addition to dedicated partnerships between governmental sectors at
the different levels (i.e., federal, provincial, and municipal) and the private
sector, are accelerating greater access to broadband Internet in many areas. At
the same time, such initiatives are somewhat lessening the burden of expanding
operator infrastructures. Another factor that impeded the realization of
profits in deploying 3G networks stems from issues in patent management . It is
hence that calls were made to “pool” the patents for LTE, and several
initiatives – including the IIT initiative in Canada, where made with this
objective. Patent pooling enables several companies to utilize each other’s
patents when producing a certain product, substantially reducing the royalty
fees.
