802.11 Ac Survival Guide Pdf

[Karmen Mcarthun]

Thenext frontier for wireless LANs is 802.11ac, a standard that increases throughput beyond one gigabit per second. This concise guide provides in-depth information to help you plan for 802.11ac, with technical details on design, network operations, deployment, and monitoring.

The upcoming 802.11ax Wi-Fi standard is the sixth generation of 802.11 standards, which the Institute of Electrical and Electronics Engineers first developed and ratified in the 1990s. IEEE began working on 802.11ax -- also known as Wi-Fi 6 -- in 2014 and expects to ratify the standard by 2020.

As with most new technologies, separating 802.11ax facts from constant hype isn't easy. This 802.11ax survival guide provides essential information about key moments and features of 802.11ax, as well as expectations around 802.11ax-capable devices. It also highlights practical advice on how to prepare for Wi-Fi 6 and dives into how the new standard will affect networks everywhere.

To gain a complete understanding of 802.11ax and what the upcoming Wi-Fi standard can do for networks, organizations should start at the beginning. Some good starting points include learning how Wi-Fi standards are developed, evaluating the necessary steps to prepare networks for 802.11ax and differentiating Wi-Fi 6 from its predecessors. Discover the fundamentals of Wi-Fi's next generation and see how it can change your network.

The 802.11ax standard will introduce several new features to differentiate it from previous Wi-Fi generations, and these elements will affect various network architectures. Some new features are updated variants of older Wi-Fi capabilities, while others were developed to improve upon past faults. Explore how 802.11ax's relationship with the other newer technologies, such as IoT and 5G, will send the networking industry into a transformative new era.

Several vendors released prestandard Wi-Fi 6 devices, including access points (APs) from Aerohive Networks, Cisco and Aruba (Hewlett Packard Enterprise). The following articles provide information on vendor releases, as well as when to consider investing in these appliances. Read about how innovative these devices are and see which would work best for your network.

Though 802.11ax isn't ratified yet, a dedicated IEEE group has worked on the standard for years. Use these articles to navigate your way through a timeline of key events, including the introduction of the name Wi-Fi 6 and predictions for when widespread enterprise adoption will occur. The standard's debut means something different to individual networks, but organizations are confident in what 802.11ax's debut will mean for the networking industry.

In early January I've updated my Raspberry Owncloud installation from Ownclud 5 to Owncloud 6. So far, everything continues to run smoothly and I noticed some nice improvements. In Owncloud 5 and before, using the web based address book was a bit of a pain as the icons for each address book entry was requested separately and the Raspberry Pi is a bit slow to respond. This has much improved in Owncloud 6, they seem to be all requested and loaded together now, which significantly reduces the load time.

Further, OC 6 introduces thumbnails for files which are generated from their actual content. Sounds nice but on a processing power limited Raspberry Pi it slows things down. Fortunately there's a configuration option to disable thumbnail use. So as far as the address book is concerned OC 6 is faster than it's predecessor and all other functions have not slowed down, despite the massive code increase of OC 6 over OC 5.

So far my main phone I have in use is not LTE capable. While I am in cities I do not mind, the 3G networks in Germany are fast enough so there is not a lot of difference to LTE. But there is one big advantage LTE phones now have in Germany, fast Internet connectivity in the countryside.

Due to spectrum auction rules, network operators had to deploy LTE on 800 MHz in the German countryside first and where only allowed to use this frequency range in cities once rural areas where covered. As a consequence there are a lot of places today with LTE + GSM coverage but without UMTS.

That means that my 2G/3G phone drops down to unusably slow GSM/EDGE in the countryside while my LTE phone in the other pocket continues to enjoy hyperfast connectivity. I've set the 'almost' in brackets in the title because I have a way out: Wi-Fi tethering. Whenever I am in a place with LTE only coverage, Wi-Fi tethering from my LTE phone provides connectivity for my 3G phone. This works very well in practice and the battery of the LTE phone powers the internal Wi-Fi access point for around 8 hours. That's usually more than enough. Agreed, it's a kludge but it works.

Did you know that there's a very easy way to trace the Bluetooth interface between a PC and a Bluetooth dongle on a Linux PC and visualize the result with Wireshark? I didn't and also searching for it on the net only revealed bits and pieces of the puzzle on different web sites. So here's a quick overview of how it all fits together.

Many Linux distributions (such as Ubunutu) ship with the Bluez Bluetooth stack. Part of the stack are a number of very helpful command line tools. Have a look at 'hcitool' (HCI stands for Host Controler Interface, a term defined in the Bluetooth specs) to get general information about connected devices and 'hciconfig' to learn more about the capabilities of the Bluetooth chip in the PC. The most useful tool, however, is 'hcidump' that can be used to trace all Bluetooth messages that are passed between the PC and the Bluetooth chip. On my Ubuntu 12.04 LTS the 'hcidump' tool wasn't installed by default but a simple 'apt-get install bluez-hcidump' does the trick.

'hcidump -X' does some basic level decoding of the messages and outputs the result in real time to the console which is an interesting first step. For more details use the 'hcidump -w filename' command to dump the raw data flow into a file. The file can then be opened in Wireshark without any conversion necessary for full decoding. The two images on the left show how a message looks like in Wireshark that establishes 'HID Interrupt Channel' for a Bluetooth keyboard and how a message looks like that is transmitted to the PC when a key is pressed on the keyboard.

When you use Wireshark make sure you have the latest version as its Bluetooth decoding capabilities have been significantly extended in the past two years. Older versions such as the one included in the Ubuntu 12.04 LTS repository can only partly decode a frame. Compiling and configuring the latest Wireshark version is a bit of a tricky thing though and I'll describe the details of that in a follow up post.

Two years ago, Vodafone Germany reported that they had transported 25 terabytes of data on New Year's Eve 2011 between 8 p.m. and 3 a.m. That was an average throughput of 7.93 Gbit/s as I calculated at the time. For the same period in 2013, Vodafone now has again given out numbers and the comparison is quite interesting. According to this report on Teltarif, the data traffic this time was 66 terabyte, which translates into an average throughput of 21 Gbit/s. An impressive increase perhaps partly also due to their efforts to provide high speed Internet access in underserved rural areas via LTE. In terms of yearly growth rate that's a CAGR (compound anual growth rate) of 62.7%.

Over Christmas, demand for Internet radio streaming must be significantly higher than during other times. Like every year, some of the stations in my favorite list started to get a hick-up on the 23rd of December. This made me wonder what people would say if FM radio today if it had been invented after Internet radio streaming and not long before?

For sure people would say that it's a great idea because it fixes the capacity problem as there is no limit to the number of people who can listen simultaneously. Which is pretty much the only advantage from an everyday perspective, until power fails and the Internet connection drops dead, but an interesting one around Christmas.

But then the number of stations at a location is very limited compared to the thousands of web radio streams one can receive, there are different stations when one is on vacation, they might not play the music one wants to hear, too much talking, too much advertisement, etc. So if we were all used to Internet radio, would a newly invented FM radio actually have a chance if it had to start from scratch?

So far I wasn't exactly impressed by French network operators and their LTE deployments. But it seems 2013 was the year they started to be serious about it. Today I came across current figures of 2G, 3G and LTE deployments of all network operators released by the French regulator and updated monthly. Have a look here for lots of interesting details.

Currently, Bouygues leads with 5.392 active LTE base stations. That compares to around 6.000 LTE base stations currently in operation by Vodafone in Germany (reference). The difference, however, is that most Vodafone LTE sites use the 800 MHz band and thus cover a wider area than those of Bouygues. 3G wise, Bouygues has 10.542 base stations, which is a far lower number than those of Orange and SFR.

Some things come and go, but Selfoss has stayed. Except for a small hiccup once it keeps doing its job marvelously and even when I'm somewhere without 3G or LTE coverage and have to fall back to GPRS/EDGE, the posts remain perfectly readable as images in the posts are only loaded if a button is pressed.

Back in May, I've bought a GSM enabled power socket to be able to reset my homecloud from abroad should something become stuck. Since then everything has been extremely stable and I didn't need it once. But then while I was abroad on vacation recently there was a power failure, quite a rare event and the first one this year. I noticed it quite quickly of course because my RSS server stopped responding.

What I found odd was that I didn't get a warning SMS from the GSM power socket as I've tested the functionality in the past and it was working then. There are a number of explanations for this, one of them being that the power outage was a bit more widespread and the GSM base station was also affected. I then sent a status query which was not answered. That had me worried for a bit. But at least I got an sms immediately after power was restored 50 minutes later.

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