Clear To Send: Wireless Network Engineering

Stephen Cooper flies from Australia to San Jose to record in-person for Clear To Send. But really he was in town for work and made time to meet with me, Rowell, to talk about different topics in wireless. Interview with Stephen Cooper We met at the Westin hotel which happened to be the quietest place downtown due to a winter holiday event occurring. He’s a Technical Solutions Architect for Cisco residing in Australia. Previously was the Ekahau SE for Asia Pacific working out of Australia. And before that he was at Dimension Data. It’s challenging to find wireless guys who understand wireless and network access control such as Cisco ISE or Aruba ClearPass. At Dimension Data Stephen had to work on these types of projects. Network access control usually falls with the security team and the wireless guys don’t have much insight into how it’s deployed. Troubleshooting is critical for wireless professionals. Understanding how the network should be working helps identifies root causes faster. While at Ekahau, Stephen was very remote from the rest of the team. He met with a lot of customers where shifting their minds towards thinking about design first and understanding fundamentals. A vendor default is not vendor recommendation. And a challenge Stephen noticed at Ekahau is customers may not necessarily know that distinction. When it comes to design, we often see that device types are forgotten and not considered into the design process. But the wireless community has been very good at bringing device types and their characteristics into light. Moving to Cisco, Stephen has been able to work with clients on wireless designs, helping with migration strategies between controllers, helping customers understand how to get onto locations services network or VoIP ready network. He’s more focused on wireless and Cisco DNA – future architecture. With Cisco’s next generation wireless architecture and intent-based network, Stephen thinks you have more flexibility with how you can deploy new controllers, but there’s still life in the AireOS controllers. There’s a large legacy install but they can still do telemetry you can use in DNA Assurance. You may not get the same level as detail compared to the C9800s. Wi-Fi Design Day was born out of Ekahau and was started in the UK. It was meant to educate people but have it a community driven event. The first event was a huge success in London and when it was announced in Australia it was also popular. The event is unique where it’s vendor neutral with experts from multiple vendors talking about Wi-Fi as well as end users talking about their use cases. This event is much smaller and intimate compared to larger conferences. Links & Resources Twitter: Stephen__Cooper Blog: wificoops.com

To deploy a high performing WLAN, in which your workforce heavily relies on, requires more than guess work. 6 Characteristics of High Performing WLANs Wi-Fi networks were originally built with coverage in mind and access points were installed in rooms where it was known to need Wi-Fi. But as businesses began migrating from Ethernet to a complete Wi-Fi only infrastructure, this made Wi-Fi a mission critical service to business objectives. We outline 6 characteristics of high performing WLANs which do away with frustrated end users and get the business back on track to productivity. Planning and Design You give your finger a quick lick and put it up in the air. Then you turn to your installer and point to randomly selected areas of the ceiling and say, “Put a WAP here, one over there, and one right here and we should be good..” This is a recipe for disaster. To deploy a high performing WLAN, in which your workforce heavily relies on, requires more than guess work. It requires a proper design which begins with gathering requirements. When it comes to upgrading the core network, Wi-Fi must be treated the same. Treat Wi-Fi as an extension of your wired network. Design is the result of thorough planning. It requires understanding how the WLAN will be used, what devices will be utilizing the WLAN, how many devices, and what applications. This is not an exhaustive list of questions but it’s a good starting point. The end result of planning and design will be a WLAN built for a productive end user experience. Planning upfront will lay the foundations to a WLAN designed to fit the business needs. A WLAN must be designed for a mobile workforce. The technical professional must have in-depth Wi-Fi knowledge and understand the knobs required to tune for the specific environment. A high performing WLAN will be designed so that there are less trouble tickets. It will be designed on the capability of the devices utilizing the WLAN, the capacity needs of the environment, and for high density of devices. Reliable Accessing information quickly and easily on any wireless device drives the mobile workforce. Wi-Fi is now the primary access. Businesses have been migrating from Ethernet to an all wireless infrastructure. That means the WLAN infrastructure must be reliable. Redundancy builds a robust WLAN infrastructure to prevent major outages. It prevents loss of productivity and loss of potential revenue. Ensure the WLAN is built with good backend infrastructure. A reliable WLAN must be capable of adapting to the radio frequency environment. It must react to adverse effects from neighboring WLANs. Interference is another productivity killer which a WLAN needs to identify and mitigate. With workforces placing an abundant reliance on cloud applications, maintaining a reliable WLAN is key to boosting business growth. Secure Mobile data traffic grew 63% in 2016, according to Cisco. There’s no avoiding the penetration of IoT devices as they take the enterprise by storm. It leaves many wondering how to secure IoT devices and their WLANs. IoT may help drive innovation but data must be kept secure and unauthorized access needs to be thwarted. A high performing WLAN must allow trusted devices to authorized data. Properly segmenting these networks is just one of many steps. A WLAN system must identify rogue access points and devices with a method of containing those threats quickly. In 2007, TJ Maxx had a cyber security breach of their credit card data because of weak Wi-Fi security. Don’t become the next headline. Good End User Experience In today’s workplace, everyone is accessing the cloud at all times. Wi-Fi is now the primary method of access to network resources. People are carrying up to 3 or 4 devices at a time and needing to get their work done from any of those devices.

François goes into what it means to be an engineer. Meet Daniel Cavazos Daniel resides in San Antonio, Texas and is a Wireless Infrastructure Sales Engineer for Ventev. Sorry, Daniel! We thought we had a photo of you but we must have missed it! What Does It Mean To Be An Engineer Definitions of an engineer: A person who designs, builds, or maintains engines, machines, or structures. A person qualified in a branch of engineering, especially as a professional. My Definition of an Engineer * Finding solutions to complex problematics * The goal of an Engineer is to solve a problem most of the time complex problem involving a high level of technical skills * Designing a new solution, a new Wi-Fi network * Updating and maintaining a Wi-Fi infrastructure * Troubleshooting a Wi-Fi issues * All these tasks require us to understand what we are doing Embrace the challenge * Once you understand this, you have to embrace it * Problem solving * Embrace problems * See them as a challenge rather than something negative. I really started to appreciate that idea working with more experienced Engineer Important Skills * Be able to understand the WHY * Planning / Research * Be able to know HOW to * Experiment * Be thorough and methodical * You need to be able to support the solution you are proposing Not only the technical skills * You need to be able to communicate * With other Engineers * With less technical persons * Explain and sometimes sell your solution to management * You need to be able to document your work * In a very detailed way for your peers * In a summarized way for management What do you think? Is it how you see your job? What other aspects of working as an Engineer are important?

This week in wireless we have a round of news to cover. Below are what we discuss on the show with our opinions. I apologize for the briefness of the show notes. I, Rowell, am traveling this week. Cisco Catalyst 9800 Wireless Controllers: https://www.cisco.com/c/en/us/products/wireless/catalyst-9800-series-wireless-controllers/index.html Commscope to Acquire ARRIS: https://www.commscope.com/NewsCenter/PressReleases/CommScope-to-Acquire-ARRIS/ Ubiquiti Networks Enterprise technology segment soars: https://www.fool.com/amp/investing/2018/11/09/ubiquiti-networks-makes-it-3-straight.aspx Golden State Warrios partner with HPE: https://news.hpe.com/golden-state-warriors-partner-with-hewlett-packard-enterprise-to-drive-connected-experiences-for-chase-center/ Bluetooth Low Energy (BLE) vulnerabilities: https://www.darkreading.com/vulnerabilities—threats/new-bluetooth-vulnerabilities-exposed-in-aruba-cisco-meraki-access-points/d/d-id/1333181 Meraki adds universal maps: https://meraki.cisco.com/blog/2018/11/universal-maps/ Rowell becomes iBwave Wi-Fi certified: http://www.ibwave.com/learning/certification-courses

Gurpreet Singh shares his story of how he got started in Wi-Fi. He also explains how to approach a large Wi-Fi deployment. Deploying Wi-Fi at Scale Gurpreet deployed a new Wi-Fi infrastructure for a large food chain and shared his experience. We talk about what is different when deploying at a bigger scale. Preparation is key Here are a few things Gurpreet and his team did early on in the project: * Plan everything * Spend time defining the solution through a Proof of Concept * Test as many scenarios as you can * Define the processes that will be used for the deployments by the different teams * Train the team * Plan everything Challenges These large deployments come with some interesting challenges: * How do you do your Wi-Fi design? * How do you choose your Wi-Fi configurations? * How do you validate your installation? Listen to the episode to hear the full story! You can get in touch with Gurpreet on Twitter https://newtowifi.com or visit his blog https://newtowifi.com.

François and Rowell discuss tips to creating Ekahau reports. 6 Tips for Creating Ekahau Reports 1 – Use testing files If you have worked on any programming project before, you will easily understand this tip. Working on a report template is kind of working on a programming project. Here is a summary of the work flow: You create your template file including your JSON tags You run it against your Ekahau project You debug the JSON errors you have Once you don’t have errors anymore, you can analyze the final generated You fix your template You run the updated template against you Ekahau project You rinse and repeat steps 2 to 6 until you are satisfied with the overall generated report In the process of testing and debugging, it is much easier and faster to get it done if you work on smaller portions of the report, one at a time. So here is how you could do it to speed up the process: Create one master template. This will be the template that you will use at the end to generate the final report. Create a second template (I call this one my testing template). You will use this one to fine tune your report, section per section. Use this template to do your testing. Once you are happy with the result, copy and paste the section into the master template and start working on the next section. This is ease the overall process of debugging, fine tuning a custom report template. Also, when working on loops, I also sometimes create an Ekahau testing file (.esx). I would have a little version of my Ekahau project with maybe 2 or 3 of the elements I am looping on. This way, the testing and tuning process is also much faster. So if you want to loop on APs, you could have an Ekahau testing project with 3 APs and only loop on these 3 APs. 2 – Put as much information as you can in the Ekahau project One of the best advantage of using custom report templates is that it speeds up the process of generating reports. In order to maximize on this, you want to gather as much information as you can into the Ekahau project itself. If you do so, you could use the template to generate most of the report for you without adjusting it too much post generation. Example of information you can configure directly into the Ekahau project: Name of the project Name of the customer Name of the Engineer Address of the location you are designingtroubleshootingvalidating Cable length from AP to MDF/IDF (2D estimation) Location of MDF/IDF Name of APs All the capacity details (number of devices, type of devices, distribution…) Network configuration details (Min. Data rate, number of SSID) You can also add notes to the following objects: Areas (you could use this to specify specific requirements for specific areas) Access Points (You could use this to add pictures, specify installation specifications…) You can also add text notes and pictures notes on the floorplan itself. All these notes and information will be retrievable from the custom template report. Yes it will take you more time to finish up your work in Ekahau. However, it will save you a bunch of time when you generate and produce the overall final report. 3 – Prepare your floor plans beforehand Let me tell you, it is way easier to spend the time to prepare the floor plans before you import them into Ekahau rather than fixing the generated images in the final report. A lot of cropping and fixing can be involved, after the final report is generated, if your floor plans are not the best to begin with. One tip would be to make sure that you work on your floor plans before importing them into your...

Rowell and François discuss their tips and advice when running a Meraki Wi-Fi network in challenging environments such as warehouse, hospitals, and dense office environments. Meraki Wi-Fi Tips There’s a big appeal for organizations to use Meraki. The ease of management is the biggest factor. With the management interface being user friendly and the hardware having a very minimalistic look and feel, there’s no question why it’s so popular. But making something easy to use does create other challenges when it comes to Wi-Fi. Some scenarios are not as easily solved with Meraki, or any other vendor for that matter. There are a lot of configurations which could lead to poor performance. We’ve seen it before with our existing clients and wanted to offer our tips. Design We’ve noticed many people opt to skip design altogether. Or maybe they are unaware that a design is needed. This is the biggest mistake. Before we dive into Meraki specifics, we wanted to take this chance to remind everyone to have a design completed by a Wi-Fi expert. Know your devices and applications Planning and design are critical. This involves knowing what type of devices will be using Wi-Fi. Those devices will dictate how your configuration will be for your Meraki network. We’ve seen many misconfigurations which lead to users complaining about Wi-Fi performance due to not knowing how the devices utilize Wi-Fi and what applications are being used. Turn off 2.4 GHz radios By default, every single 2.4 GHz radio is enabled. In a warehouse, every AP can hear each other because of reflections and open space. Signal travels very far. In one example, a warehouse was seeing over 60% channel utilization on every AP in the 2.4 GHz spectrum. After about half of the radios were disabled, the channel utilization dropped to under 20%. A design will provide indicate which AP should or should not have a 2.4 GHz radio enabled. Coverage holes should not be created if devices must use 2.4 GHz. Channels With every radio being enabled by default, we must keep in mind what channels are being used and how much we can reuse. Using wider channel widths can look appealing because of the high throughput but at the cost of minimizing how many channels you can reuse in your environment before causing co-channel contention. Again, a design will produce a channel plan in both 2.4 GHz and 5 GHz. Our guidance is to stick to 20 MHz or 40 MHz wide channels. Transmit Power All we have to say here is tune down the power. There’s no need to transmit at full power. That signal travels very far and can contribute to co-channel contention. Sometimes the AP cannot hear the client device transmitting back to the AP because clients don’t have the same power capabilities as APs. Use a design to determine the transmit power settings of an AP. Placement is key Again, we must reiterate the benefits of doing a design. Placement is important especially when dealing with scanner guns, roaming clients, and VoIP calls. APs placed away from obstruction will provide the best performance and will minimize the amount of client issues. External antennas help tremendously Sometimes omnidirectional antennas just don’t do the job. We need to provide better quality signal to the clients and this is where antennas help a lot. You can shape the signal you want, for example, down an isle. Or if you need to wall mount an AP but direct a signal to a specific area then an antenna can do that job for you. Client balancing Sometimes the client balancing feature within Meraki can cause issues with clients on voice calls. I’ve seen clients on a VoIP call get dropped due to client balancing. In a warehouse, scanner guns weren’t roaming properly because some APs had more users than others so client balancing was affecting how users were roaming.

Coming off the end of the CWNP WiFi Trek conference, we go over our tips for becoming a CWNE. Tips on Becoming A CWNE Sometimes, we get sone questions from you guys about what it takes to become CWNE and if we have any tips. After seeing how many people at the CWNP WiFi Trek conference wanted this kind of advice, we decided to combine our tips together and provide our insight. These tips are based on our own experiences and we hope you find it helpful. Take it one step at a time Learning the 802.11 protocol takes time. Don’t rush the learning process. Understand what you’re trying to learn and explain it to others as a way to reinforce the learning. Start taking frame captures Get started early when it comes to doing frame captures. As you begin getting into the nitty gritty details the more you’ll understand as you get into the professional level certifications. Learn how to capture frames during your CWNA certification study. Do it alongside the theory and it will be engrained in your mind. Get ahold of the standard Reading about wireless from the 802.11-2016 standard is getting it from the source. Although it is dry material, it is the actual standard in which all training material is based out of. Structure studying Book the exam before you start studying for the certification. This changes your mindset and gives you and end date to complete your studies. If you don’t do this you’ll make more excuses as to why you don’t have it done. Set it in the calendar and create a schedule. Let everyone, including your family, know ahead of time. There will be some time commitments to obtain your CWNE. Take notes Write your notes down in the form of blog posts. This is a great way to get your published content out there. Utilize the Notes app on iOS and macOS. Evernote is another useful note taking app to keep all your content together. It will make it easy to go over while in line at a store or during a break from work. Get ahold of equipment It’s much easier to get ahold of wireless equipment nowadays. Join a Meraki or Mist webinar and you can get an enterprise grade access point for free. Or check out the WLAN Pros Lending Library (United States only) to borrow some equipment to further your learning. If you have to, use your consumer grade home wireless for learning too. They all speak 802.11. Get endorsers that know your work Endorsers know about your work. This could be your colleague or manager. An endorser does not need to be a CWNE. Do not broadcast an email asking CWNE’s to endorse you, especially if they don’t know you or your work. But you can ask a CWNE or anyone else to review your essays. Focus essays on the Pro level certs We’re often asked what your essays should be written about. Focus a paper on each of the professional level CWNP certifications, Analysis, Design and Security. That makes it easy. If you can’t write something on each then pick one that best speaks to your experience. Each essay should demonstrate your technical knowledge as a CWNE. You’ll need great grammar as well. It doesn’t have to be a novel. Keep it to about 2 pages and don’t be afraid to add images and tables to your essay. Publish articles Write a blog about what you’ve learned from your CWNP studies. Or blog about your experiences out in the field in regards to wireless. You can also start a podcast about wireless or even create your own YouTube videos. You don’t have to write any whitepapers but you do want something published in your name. A blog is the easiest way to get started. Links and Resources * CWNP WiFi Trek...

Ookla, makers behind Speedtest.net, have acquired Ekahau. Ooklahau Announced October 10th, 2018 Ookla has acquired Ekahau. The makers behind Speedtest.net are getting their hands into the Wi-Fi world by acquiring the maker of Wi-Fi validation tools. It’s a headscratcher of an acquisition. Speedtest.net is Ookla’s flagship product. It’s used by many people around the world. So why an interest in Ekahau, a maker of Wi-Fi validation software and tools? My first guess is Ookla sees the future of Wi-Fi. They could build their own set of “speedtest” tools for Wi-Fi networks with the help of Ekahau. In return, this provides Ekahau with more resources to put towards Ekahau Site Survey and the Sidekick. It’s a way to further development. It’s only natural to have reservations when the company in which you use their tools so often gets acquired by someone else. We just don’t want to see our favorite products fall by the wayside. As I discuss with Jussi Kiviniemi, that’s not the case. They will continue to operate as normal. Their plans for Ekahau Site Survey development are still on schedule, they continue to work on the Sidekick, and continue to work on other projects. What was evident here was the culture match between Ookla and Ekahau. Jussi Kiviniemi speaks strongly of this and is one of the major decision makers for the approval of the acquisition. Listen in on what Jussi has to say about the acquisition as we have breakfast at the Four Seasons in Palo Alto.

Nyansa provides visibility into your Wi-Fi network. What can you do with it? Analytics Data & Wi-Fi Coming off Mobility Field Day 3 (MFD3), Nyansa brings a couple of updates. There’s a lot of data collected and presented onto the dashboard. What could be challenging is understanding all the data you’re able to see. And it’s not just data from the Wi-Fi equipment. Nyansa’s product will gather information from other systems of your network such as RADIUS servers, DNS servers, and other data collected from SPAN ports. As we all know, Wi-Fi issues are often not Wi-Fi at all. Collecting this much data really gives you a broad look at how the network is performing for the clients. Where Nyansa can shine further is by providing data correlation to show you what’s the most critical issue or most impact there is on the network. The data is there in the dashboard but if there’s specific troubleshooting you’re trying to perform, you can dig into further based on clients, APs, DNS servers, etc. Full Client Experience What are we trying to get at with all this data collection and analytics? We want to understand how the clients are doing on our Wi-Fi networks. Down from Layer 1 and 2 all the way up to the Application performance. All these stats are collected within Nyansa and analyzed. Nyansa now has the a client agent which can be installed on macOS and Windows. So much of the data we have been seeing from many solution providers is the point of view of an access point. Now with a Nyansa client agent, we can get a full picture of how clients are performing. The ability to look at this information as a third party rather than from the vendor’s point of view can sound compelling. In a way we can actually begin holding various vendors responsible for their claims or help to improve client drivers, for example. White Papers Where Nyansa can really stand out is by providing white papers containing analysis of how Wi-Fi is performing based on vendor/drivers/applications and more. Recently, Nyansa released information gathered across their client base which shows the impact of the Cisco and Apple partnership. Do we see better roaming with Apple devices because of this partnership? This is the kind of data which can create an impact in the industry. It might not be the actual direction Nyansa wants to go as a company but that type of information is at their grasp. Final Thoughts Nyansa collects a mind blowing amount of data. Where they can improve is in providing better root cause analysis to help point an operator to an actionable result. Having this amount of data at your fingertips allows someone to get detailed information into how their clients are interacting with the network and how that experience is for the user. Where Nyansa may have a missed opportunity is in analyzing different vendors, drivers and even security. We haven’t really seen Nyansa utilize AI to the extent with other vendors but there’s potential. Overall, more information collected the better but can lead to information overload if not handled properly. Links & Resources

We discuss Mist System’s bet on Artificial Intelligence in Wi-Fi Mist Goes All In With AI Mist delivers an update from a year ago when they announced their Artificial Intelligence (AI) for Wi-Fi, Marvis. With a lot more features implemented, it’s possible for a user to ask questions in a natural language and instantly get a response from Marvis. Our discussions come from Mist’s presentation at Mobility Field Day 3 (MFD3) where Rowell participated as a delegate. The folks over at Mist are very confident about their AI solution, Marvis. So much so they use it with the tickets that come in from their customers. Marvis will look up the issues for you. Just with a few simple questions. You can ask questions such as: “How was the site Corporate Headquarters doing during yesterday?” The response you get are the problems affecting that site. Further from just telling you the issue, you can drill in further, correlate data, and get down to the root cause. The amount of data that is in front of you can be staggering. Ultimately, that information is actionable. There’s a lot of potential with Mist being a cloud-managed Wi-Fi solution. You can check it out for yourself in these videos from Mobility Field Day 3 (MFD3). Links & Resources DeMISTifying Wi-Fi Issues

Understanding OWE operation from the Aruba Networks demo presented at MFD3. Aruba Networks Demos OWE Opportunistic Wireless Encryption (OWE) is a security improvement coming to open SSIDs. It’s aimed at securing the insecure. We see it everywhere. A Wi-Fi network completely open for clients to join. It’s unencrypted traffic between clients and the AP. OWE was demoed by Aruba Networks at Mobility Field Day 3 (MFD3) and I was able to capture the frames during the demo. Aruba needed to build a custom supplicant using Ubuntu in order for this demo to work since there are no working clients supporting OWE yet. There was an AP broadcasting an SSID, MFD-OWE, in OWE Transition Mode. An SSID in OWE Transition Mode will utilize 2 BSSIDs. One for the Open SSID, for clients that do not support OWE, and another BSSID for the OWE-capable SSID. That’s something to keep in mind for OWE Transition Mode. When most clients support OWE, an SSID strictly supporting OWE can be configured. In the demo, Aruba Networks created a custom supplicant within Ubuntu since there are no OWE capable clients available. In a Probe Response to the client, there will be an Information Element containing the BSSID and SSID for an OWE-capable client to send a Probe Request to. The client sends a Probe Request frame to the OWE SSID, which is a hidden SSID. Within the Association Request frame, the client will include an RSN Information Element. Within that RSNIE there will be the MFP requirement needed in OWE. After association a 4-way handshake will follow and when complete, transmissions will be encrypted. Information you’ll need for the pcap file: Open SSID: MFD-OWE BSSID of MFD-OWE: 20:a6:cd:60:00:b0 OWE SSID: _owetm_MFD-OWE2340208851 BSSID: 20:a6:cd:60:00:b1 Client MAC: 9c:b6:d0:d7:ce:dd Links and Resources * OWE pcap file * WiFi Explorer Pro File

David Coleman and David Westcott join the show to discuss the new release of the Sybex CWNA Study Guide. Sybex CWNA Study Guide, 5th Edition David Coleman and David Westcott have released an updated version of the Sybex CWNA Study Guide, 5th Edition. It’s been refreshed for the CWNA-107 exam and it’s packed with a lot of content. As Coleman and Westcott will describe in this episode, it’s been quite the process completing the study guide. With so much Wi-Fi technology out there, and being backwards compatible, there’s a lot to include. What you’ll also find is information for the upcoming 802.11ax. With the 5th Edition of the Sybex CWNA Study Guide, there has been a complete overhaul. The study guide doesn’t follow the objectives in order. Coleman and Westcott have reorganized the content in order for it to have a natural flow. There’s more of a logical chapter order. There’s a new chapter about WLAN design concepts and a new chapter on WLAN troubleshooting. In addition to hearing about the book, Coleman and Westcott talk about how they got into Wi-Fi and ended up writing the CWNA Study Guide together. We discuss the process in writing such a technical book which includes a lot of research of the 802.11 standard, testing, and editing. You’re not getting a regurgitated version of the 802.11 standard in this study guide. You’re getting a lot of real world information that will be more than useful for the CWNA-107 exam. It will be a study guide and a reference. Links and Resources * Sybex CWNA Study Guide, 5th Edition * Coleman on Twitter * Westcott on Twitter Enter To Win a Copy of the Sybex CWNA Study Guide, 5th Edition

Eric Johnson talks about how MIMO works. We also talked about outdoor Wi-Fi, MU-MIMO and 802.11ax.   Nick Turner We interviewed Nick at Cisco Live US 2018 at the Ekahau booth (he works for Ekahau). He is the reason why Ekahau template reports are so popular. You should also check out his blog where he shares some of his Mac Giver skills. MIMO Here are the main topics discussed during this episode: * History of MIMO and when it got introduced in Wi-Fi communications * Presentation of what MIMO is and how it works * What are the differences between SISO and MIMO * What is antenna diversity? Why does it help to use multiple antennas? * How do we obtain multiple spatial streams? * Does MIMO work outdoor? * What is cross polarization and why is it useful outdoor? * What is Tx beamforming and how is it related to MU-MIMO? Eric shared a lot of useful information and it was not always easy to explain it in an audio format! Listening to him, we could picture his hands moving while explain some concepts. We would like to thank him for taking the time to participate and share some valuable knowledge. We ended the interview on a positive note about MU-MIMO and 802.11ax. You can follow Eric on Twitter at @ej_wireless and find more of the content he created for conferences on the Airheads community website.  

Jim Palmer talks about how he performs RF filtering and isolation to improve client connectivity. RF Filtering and Isolation We welcome Jim Palmer to the podcast. He’s one of the newest delegates for Mobility Field Day 3. I look forward to meeting Jim in person and learning more about him. Jim works at a major airport. That comes with a lot of RF challenges with transient customers. The customers are not the only problem. An airport utilizes many different frequencies. DFS channels can be a challenge. Jim has a background in radio and public safety which comes in use at the airport he is employed at. At the airport Jim works at, they use quite a bit of external antennas. 65% of their installation is external antennas. So why do any kind of RF filtering and isolation? To provide better stable Wi-Fi service. Using RF filtering and isolation does increase the SNR for the clients and decrease the noise floor. It’s been used to help get scanners connecting to Wi-Fi more reliably without adding thousands of dollars for a solution. To achieve this, Jim uses bandpass filters connected between the antenna and the AP. This bandpass filter essentially filters out frequencies except for the one the filter has been designed for. It can be a specific channel on 2.4 or 5 GHz. Listen to the full episode to hear Jim on how he uses these bandpass filters to improve Wi-Fi at his airport. Links & Resources * Bandpass filter for 2412 MHz * Jim on Twitter * Jim’s wireless blog