Integrated Wireless VoIP Solutions For
BY RICH WATSON
In an earlier article, the basic concept of a wireless VoIP handset was
described along with discussion of some of the challenges faced when
bringing a quality product to the market. To develop such a product with a
strong commercial value-add, it must be wrapped into a total ï¿½solutionï¿½ and
this typically means integration into a telephony system. Making calls
between two wireless phones in the same network has limited value, but a
wireless phone that has all the features of a desktop phone and can call
Momï¿½now, thatï¿½s value!
By providing the same feature set as found on a desktop phone (e.g.,
transfer, conference, park, hold, etcï¿½), a wireless handset becomes a real
value-added business tool. Extending telephony connectivity to co-workers,
customers, and suppliers through a wireless telephony integrated solution
can offset the basic availability problem posed by the mobility of todayï¿½s
office worker. Analysts estimate that some 65 percent of all phone calls end
up in voice mail. This article will discuss the currently available options
for providing a wireless VoIP solution, along with a peek into the future.
In general, providing an integrated in-building wireless telephony
solution means coupling the wireless handset with a ï¿½gatewayï¿½ that
integrates into the on-premise PBX. It is through such gateway products that
seamless access to the PBX can be provided. There are, however, a number of
variant approaches to such solutions. Additionally, these options are
expanding as the telephony industry itself embraces VoIP.
Businesses that adopt a wireless telephony solution will most likely require
integration into their legacy PBX systems. Since a PBX is a rather large
investment, it is typically not a consideration to install a new PBX just to
add support for some additional wireless handsetsï¿½thus the ï¿½adjunctï¿½
solution approach. Basically, this product architecture approach provides a
ï¿½gatewayï¿½ solution that interconnects to the PBX and emulates either an
analog or digital handset phone line. The gateway then acts as a proxy for
the wireless handsets and connects them to the telephony network over an
802.11 wireless network through a defined call control protocol. This
approach provides a way to preserve the PBX investment while supporting
integration of a new wireless solution into the overall business telephony
The gateway approach is predominant in the current market because major
telephony vendors have not fully embraced VoIP as an integrated service
provided by the PBX itself, while customer adoption of VoIP is advancing
rapidly. There are a number of gateway solutions available on the market,
but some consideration should be taken as to how they integrate into
particular customer environments and the breadth of features supported.
Because the gateway is often a product of a third party (not the prime
PBX vendor), integration is provided, but some limitations may exist with
these solutions. If your company is investigating a wireless VoIP solution,
it is important to understand the possible limitations and how they might
impact your particular operation. Some of the limitations found with the
currently available gateway products are:
Scalability -- Gateways are most often designed with a
limited capacity for handset support. By estimating the number of active
calls that need to be supported, one can judge the true capacity of any
gateway solution. Of course, multiple gateway units can be configured onto a
PBX, but limits in active capacity can impact the total cost and
manageability of such a configuration.
Limited network capability -- Making a product/vendor
selection should involve understanding the network feature requirements.
Some solutions place restrictions on how they can be integrated into a
multi-subnet network. Items such as remote management come to bear with this
consideration. Enterprise customers will need to understand these criteria
Limited feature access -- Some cost effective gateway
solutions provide only a limited feature set. Functions such as Caller ID,
Voice mail message indication, and others may be important to an operation
and need to be considered when making a gateway selection.
Now that we understand some of the considerations of a solution mix, it
is also important to understand the basic PBX connection options.
Any of the ï¿½connectionï¿½ methods mentioned in Table 1 can be suitable, but
will depend on the specific requirements of the installation site. When
evaluating a vendorï¿½s solutions, be sure that a clear definition of
telephony requirements is provided and reviewed. The good news is that there
are reliable adjunct solutions available today that provide good voice
quality and sufficient features to make it a true value add.
One dynamic that is clearly evident in todayï¿½s market is that of the
telephony vendorï¿½s eager support for VoIP solutions. Most market analysts
predict that sales of VoIP PBX solutions will surpass the traditional TDM
solutions some time in mid-decade (around 2006). What this means to the
enterprise or commercial VoIP buyer is that additional solutions with higher
levels of integration will be commercially available. It takes only a little
literature search to find that all major telephony vendors currently offer
either (1) hybrid VoIP systems, and/or (2) pure VoIP solutions as part of
their product line. This market mega-trend results in one major impact on
the resultant configurations: no gateway requirement.
The ï¿½nativeï¿½ VoIP support provided by these products affords solutions
ï¿½ Reduce the number of vendors involved in the deployment;
ï¿½ Incrementally lower the cost per handset (are more cost effective);
ï¿½ Typically extend the functionality and reliability of the system; and
ï¿½ Potentially support VoIP toll bypass capability.
As ï¿½nativeï¿½ VoIP solutions make their way into the marketplace, industry
and enterprise businesses will begin a wholesale adoption of this technology
simply because of its wide industry support and cost benefit over older TDM
systems. When investigating a VoIP solution, it will be important to work
with the telephony vendor and understand how their wireless VoIP offerings
(if any) integrate into the whole solution being offered. As the technology
finally matures into the market, the compelling ROI and lower total cost of
ownership will make VoIP and wireless VoIP a success.
There are solid solutions in todayï¿½s market whereby a business may deploy a
wireless VoIP product and leverage their existing PBX investment. Contacting
the wireless VoIP phone manufacturers and learning about the connectivity
options that they offer is the best method for understanding the ï¿½systemï¿½
option. Integrating a wireless VoIP solution into a configuration that
utilizes legacy PBX systems may involve interfacing with multiple vendors
and the wireless phone vendor must be knowledgeable about these options.
Learning the configuration options will be key in determining the proper
final product configuration.
If your current telephony vendor offers a VoIP solution (VoIP desk sets
and/or PDA software), they will most likely offer a compatible wireless VoIP
solution. Whether your final solution is a hybrid-PBX or a full iPBX, it
will be the telephony vendor that is most knowledgeable about any available
wireless VoIP solutions.
The final word regarding planning the deployment of a wireless VoIP
solution is that no matter what vendor(s) you purchase the components from,
it remains very important that the underlying installed RF 802.11
infrastructure be certified for voice coverage and provides key voice
Richard Watson is director of telephony product marketing for
Symbol Technologiesï¿½ Wireless Systems
Division in San Jose, CA. Prior to taking on the marketing role for Symbolï¿½s
NetVision family of WiFi Telephony products, he managed the software
engineering team for three years and was responsible for developing Symbolï¿½s
WiFi Telephony products.
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