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Wireless voice over internet (VoIP), places extreme demands on your network. A slow network can be frustrating to healthcare users as they need realiable communications. This white paper examines the factors that lead to poor VoIP call quality and outlines the best practices for monitoring, analyzing, and troubleshooting VoIP networks using WildPackets OmniPeekTM
Download Finding_Fixing_VoIP_Call_Quality_Issues.pdf
The leader in the in-building prediction software tool, www.ibwave.com has the first ever industry vendor neutral database of wireless components. Mario has done a fine job taking his company to the next level.
All the more reason to have reliable in-building coverage. Legacy paging is being displaced. It is interesting that a medical device company is helping the clinical side with communication technologies.
The need for reliable communications does not stop at the door of a building. Increasingly public safety entities, commercial wireless providers and wireless users require reliable communications inside buildings and where applicable, inside tunnels. For public safety, reliable coverage is often essential throughout a broad jurisdiction, including coverage on-stree, in-building, and in-tunnels. In such cases, there is no substitute for a properly designed dedicated mission critical communications systems with sufficient transmit sites to provide the level of signal required for reliable coverage anywhere within the jurisdiction, whether on the street or indoors. This paper covers the basics of in-building systems, techniques to minimize the risk of interference, and engineering best practices to provide robust in-building coverage.
Meeting quality of service requirements for medical devices on a wireless network is essential for success. To ensure this quality of service, application testing must be conducted. Quality of service simply means the expectation is that the communications links for a medical device on a wireless network take precedence over any other data and voice traffic. But how you do actually ensure that the medical device within this network has priority, and who is going to take responsibility for ensuring the needed quality of service? In concert with www.veriwave.com, Integra Systems, Inc. is in final stage of the publication of a multi-faceted article covering many subjects that will be due out in November 2008, in Biomedical and IT Horizons, an www.aami.org publication.
After publication the complete article will be posted on www.veriwave.com site.
What are the needs and requirements for consistent in-building cellular and public safety signal converage in hospitals today? Ideally, digital signal processing and narrowband filtering should be used for obtaining quality cellular and PCS signals. The selection of the overall macro in-building design is important, together with the correct selection of the individual components. Together these choices will provide mission critical or life critical communications for cellular, PCS and public safety communications. There have been traditionally two ways to bring the cellular and PCS signals inside a building environment: either use a dedicated micro-cell base transmitter station (BTS), or a repeater. Most healthcare environments can get by with a traditional repeater due to capacity requirements. It is important to go to the technology that can take the signal or multiple signals from the macro (outside environment), to repeat and amplify this signal inside the building environment. It is this critical piece at the front end that determines the interplay of signals throughout. Carriers in some instances mandate digital repeaters, especially as far as the PCS band is concerned. They only want to be re-radiating their own spectrum. Many traditional in-building systems used broadband repeaters, which essentially applified all the carrier signals to include harmonics. The advantage of using digital repeaters is that they allow you to precislely control which frequecies you amplify and repeat. This actually provides better quality of signals without the risk of voice or data signal quality going down. Some broadband signal repeaters automatically take a broad range of frequencies and amplify all of them, thus including the undesired frequecies, such as harmonics and interfering frequencies. During a major emergency, often many first responders - ambulances, police, fire, and EMTs - could arrive at the healthcare facility at once and could be trying to communicate at the same time. In this case the signal strength form the broadband signal repeater may decrease when it is most required. There also have been instances when broadband singal repeaters interfered with mission critical requirements. These situations should be mitigated as many public safety and P25 networks move to the the new NPSPAC band 806-809/851-854MHz. How these changes affect you depends on which part of the country and which wave of re-banding that you are in. Frequency agility is the key here. Frequency agility includes the ability to change filter configurations to support virtually any passband combination within a specific set of wireless frequencies. This agility solves the problem of rebanding or augmenting of existing channels requiring a forklift repeater upgrade. Mitigation of adjacent channel interference should be provided by allowing the fine tuning of band edeges to eliminate or mitigate adjacent band interferers. There should be the ability to provide custom filter sets and filter plots prior to implementation of distributed antenna systems.
Pictured is a digital repeater designed for use within enclosed structures where sufficient signal strength from local cell sites to operate cell phone or data cards is limited or unavailable. Digital signal processing is utilized to achieve the highest level of performance and spectrum agility. DSP filtering provides unmatched selectivity, which helps to overcome difficult RF problems such as adjacent channel interference.
Much has been written about cell phone usage interfering with medical equipment, (see the attached detailed article from Stephen K. Olsen and I.) Generally, is is my opinion that the effect from cell phone usage is often-mis-understood. Cell phones can trasnmit at relatively high power levels for (perhaps 1 W), for short periods of time; such as during the ring cycle. However if the cellular device is in a resonably good coverage location, the power control algorithms within the phone and the cellular network will call the cell phone to transmit at much lower levels (potentially under 5mW), which is really not a problem. The rationale for a DAS inclusive to the enterprise is to provide a consistent and pervasive signal level of -85dBm (-70dBm for data in some cases). Without this consistency of the optimal signal strength, the uplink that is driving the higher power from the client device can actually decrease the battery life. Witness when you have two bars on the phone in the macro environment, the life of the battery on a charge descreases in an exponential fashion. WLAN client adapters in medical devices (patient monitors, infusion pumps, and patient worn telemetry), are somewhat power hungry, and yet these mobile devices need to operate in such a way to maximize battery longevitiy. Ideal on patient telemety at least two days. In perhaps a discrete WIFI architecture, whereby this is some contention on roaming and signal strength client to AP .configuration 1:1, this in theory could be somewhat a more of a current drain, however this needs to be evaluted on each enterprise model.
While much has been discussed about the CAPEX (Capital Expenditures), i.e the actual cost of equipment for wireless pervasive connectivity, there has been less discussions on the the OPEX (Operational Expeditures), when in summation, it should be expanded to the TCO (Total Cost of Ownership). In looking at WLANS (Wireless LANS), there have been a large diversity of engineering implementations which is based upon experience and sheer knowlege base. Like countless VARS selling wireless gear, it is important to look at their depth of experience and experience with deployments. Gartner estimates that 39% of the the cost of owning a traditional wireless network is constrained in operational costs and defined in a "Hourly cost for technical services, planning, process maangement, and service desks". - Wireless LANS have a higher TCO, but can raise productivity, June 2004. The soft costs, but not realized are the expectations set for data and voice communications, but then perhaps this is not the realized productivity because of lost connections and and/or poor voice communications quality. All of this leads up to that the fact that we have look at the indoor wireless wireless space as a planned and designed enginneering model. If we look at all the services (WLAN, cellular, PCS, Public Safety, Paging, WMTS), again from a holistic model, conducting at the start the right planning and predictive model will impact the OPEX and TCO. It is realized from an in building model that combining all of these services onto a distributed antenna systems model does make sense, however this does require a bit of RF and design expertise not always resident in the typical healthcare IT department So I agree with InnerWireless that is it is essential for the proper design up front for all the services and applications to be designed with the mission critical/life critical and guaranteed coverage maps and signal levels. This will allow for the correct design methodology and optimize all applications that will overall lower the OPEX. For example, it does not make a lot of sense to design a broadband or WLAN network only when you pass a lead lined wall in radiolgoy for the propogation of the broadband or WLAN signal to fall off the cliff and hence the connection is lost. So going back to Gartner, if you could reduce the 39% of costs for technical services by proper plannig and engineering a holistic wireless environment up front, why not? Another cost, but not not realized is the physical placement and running of ethernet cable to each every access point (AP). In the old days, you had to worry about running power, but not with POE. Another soft cost is is the is estimated of around $500 to co-locate each AP, but this again if you have a soft ceiling. What if you have a hard ceiling, or old buildings that require abestos abatement, or really soft costs of disrupting the day to day clincal operations? Co-locating the AP(s), in the IDF could reduce this cost signficantly and decrease the disruption in the clinical space (i.e breaking into the ceiling space) Plus when migrating to evolving wireless standadrs such as 802.11n, the migration of AP(s), is in the IDF not the ceiling space. Again OPEX to the TCO. As the LEED building initiative continues (The GREEN environment), the actual physical building will act as a barrier to the penetration of the macro environment. Innerwireless states they use 60% less power (attribute this to a passive design (di-plexer/triplexer) in the IDF), this again adds to bottom line savings to OPEX and contributes to LEED initiatives, i.e. lower HVAC costs. While providing a unique design to each RF enviromnent, this will perhaps allow an overall CAPEX savings. This all adds up to a requirment perhaps to spend the CAPEX up front to engineer and design the proper overharching wireless ecosystem. To provide pervasive wireless coverage on a distributed antenna system for these services demands that you engineer and design to the correct signal level and link budget. While these CAPEX dollars up front for the engineering design may not be fully understood; they will in the short and long term be realized in lower OPEX because of lower technnical support calls and then life critical enterprise wireless network will be realized with all optimized wireless applications thus impacting the TCO.
A couple of years ago when I spoke to Neil Diener at Cognio, I saw the value of real time spectrum analysis for the healthcare environment, especially with the proliferation of WLAN(s). Now with the concern of EMI, these types of tools just make sense. Oh, Cognio is now a part of www.cisco.com I did have discussions with Neil about "would this also make sense for WMTS", what about creating this WLAN Card Spectrum Analyzer to cover all the in-building frequencies and what about monitoring this via a NOC? See Twenty Myths of WIFI Interference by Cisco Systems, Inc.
Download prod_white_paper0900aecd807395a9.pdf
I recently had an email concerning the security issues/or propensity of WPA2 for medical WLANS, specifically medical devices. While several companies like AirDefense, (now a part of Motorola) have excellent solutions, it should be noted that www.arubanetworks and Juniper Networks have partnered to provide a FIPS Validated 801.11i Security for Government LANS. Until recently, the only wireless option available to goverment agencies has been to deploy a Layer 2 encryption overlay on top of their wireless infrastructure (per Department of Defense Directive (DoDD) 8100.2). While I agree that there are signifcant radio (RF) management and intrusion detection services (IDS) with today's centralized mobility systems available today, if the CIO of the healthcare IDN has a comprehensive strategic plan, then it is believed that this is a null issue. If the DOD has the compliant solution, it should be strong enough for the healthcare environment of today. Aruba and Juniper are the only partners that can offer a comprehensive FIPS validated 802.11i solution today. A modified driver is needed to run 802.11i in a FIPS-compliant configuration, but these drivers are not available for all devices and platforms. Juniper and Aruba have jointly developed the xSec protocol to address this problem. XSec is a standards based Layer 2 protocol that can provide FIPS-compliant Advanced Encryption Standard (AES) encryption over off the shelf 802.11 adapters and drivers.
Download wlan_security_what_hackers_know_that_you_dont.pdf
