Showing posts with label Wi-Fi. Show all posts
Showing posts with label Wi-Fi. Show all posts

Monday, 30 November 2020

Three New Standards to Accelerate 5G Wireless Wireline Convergence (WWC)

It's been just over a year since I wrote a detailed post on what I called '5G and Fixed-Mobile Convergence (FMC)'. The technical term being used in the industry for this feature is Wireless Wireline Convergence (WWC). 

Broadband Forum, the communications industry’s leading open standards development organization focused on accelerating broadband innovation, standards, and ecosystem development has just announced the publication of three new standards to accelerate global 5G adoption. The press release said:

Building on the Forum’s mission to drive a future consolidated approach to 5G, the standards will reduce development time, as well as capex and opex, from the traditional disparate fixed broadband and 5G networks. Ultimately, they will deliver a common and managed broadband experience to the end-user whatever the final connectivity technology.

There are three major sets of technical specifications that have been finalized, including 5G Wireless Wireline Convergence Architecture (TR-470), Access Gateway Function (AGF) Functional Requirements (TR-456) and Device Data Model (TR-181). Together, these documents provide functions and interfaces for Fixed Mobile Convergence (FMC), the AGF, and customer premises equipment (CPE) such as 5G-enabled routers.

TR-470 – produced in conjunction with 3GPP – describes the 5G FMC architecture, providing a high-level guide for network architects and planners and enabling fixed and mobile functions to coexist over a shared infrastructure. This will facilitate multi-access connectivity and give consumers a seamless, access-independent service experience.


For operators, the network functions required to operate their infrastructure will be streamlined and common technology, on-boarding, training, services and subscriber management between fixed and mobile divisions can be achieved. Furthermore, additional revenue streams will be created, with FMC extending the geographical reach of 5G core networks and the service offering of fixed networks.

TR-456 describes the functional requirements of the AGF. The AGF resides between fixed access networks and the 5G core network to support 5G and wireline Residential Gateways, creating a truly converged deployment. Alongside this, Broadband Forum’s Device: 2 data model (TR-181 Issue 2 Amendment 14), which is used by User Services Platform (USP), has been extended to address 5G Residential Gateways. The Device: 2 data model applies to all types of TR-069 or USP-enabled devices, including end devices, Residential Gateways, and other network infrastructure devices

In addition, the Functional Requirements for Broadband Residential Gateway Devices (TR-124) specification is expected to be finalized in Q4 2020. Moving from the network into the home, TR-124 has been extended to add requirements related to the 5G Residential Gateway extending the 5G control plane to the premises to open up new service opportunities with real time fulfillment.

In the video below, David Allan, Work Area Director for Wireless-Wireline Convergence at Broadband Forum and Christele Bouchat, Innovation Group Director at Broadband Forum discuss what is coming up in the next phase of 5G work and what opportunities this has opened up for the industry

WWC has a great potential to allow wireline and trusted/untrusted Wi-Fi to work with 5G so I am hopeful that operators will adopt this sooner, rather than later.

Follow the links below to learn more about this feature.

Related Posts:

Monday, 2 December 2019

Guest Post: Exploring Network Convergence of Mobile, Broadband and Wi-Fi

This is a guest post by Ben Toner, Founder and Director, Numerous Networks


Are multiple networks better than one?

How many articles have you read with a title similar to "Which technology is better, 5G or Wi-Fi6?" If, like me, you regularly use Wi-Fi and cellular (I still use 4G though) then you might find it hard to take sides.

Enter Network Convergence - the concept of bringing multiple networks together to get the best of them all. Imagine, as an end user, not having to decide which network to use but instead feeling satisfied that your data was traversing the best combination of networks at that moment in time.

Imagine a business traveler being connected to Wi-Fi which is slow or busy while trying to take that all important conference call while sitting in an airport. Because you are roaming you want to use that Wi-Fi but you do not want to compromise the video call quality. If your network and device could work together to use just enough cellular data to supplement the slow Wi-Fi so that you stayed within your daily roaming quota but never lost a moment in the video call - then you would probably be very happy with that service. Better still, as you start walking off, if the call transitioned from Wi-Fi to cellular with no dropouts or hangup then you might be delighted!

Earlier I underlined best because that in itself is somewhat complicated.  The example above is easy to desribe but quite hard for to achieve within a framework where all possible scenarios are handled that well, for every user. The common questions which need to be factored into any such choice are:
  • What do I as the end user want? 
  • What performance can each network deliver. 
  • How important is the transfer of content at that time and 
  • How much am I willing to pay for it (how many MB of my data plan am I willing to use?). 

This is one of the challenges that we cannot easily solve today, but technology is being developed to help in that process. The operators and device vendors are working within standardisation to develop technology which can provide such a converged service. However at this time there is still a rules mechanism behind it all which does not really describe how user input and preference is going to be captured.

In the last 10 years I have witnessed many battles within service providers when deciding what "one size fits all" service to offer everyone when deciding how to make service provider Wi-Fi available to their customers; all fuelled by my points above.

A lot of concepts are well designed and somewhat mature but deciding exactly what will be implemented in standards is currently ongoing.

In the following slides and video I introduce this whole concept of Network Convergence. The following content introduces the concept and then takes a detailed look at the ATSSS; technology being defined in 3GPP. I also have highlighted the technologoies you can get hold of today to try out network convergence.

I encourage you all to download the example technologies and try convergence for yourself. I'm eager to hear opinions of what technologies work best for each of you. And better still, what is not being provided which you think should be...

Looking forward to your feedback and answering your questions...





Ben Toner
Founder and Director, Numerous Networks


Related Posts:

Thursday, 7 November 2019

Introduction to 5G ATSSS - Access Traffic Steering, Switching and Splitting


Last month we made a short tutorial on 5G and Fixed-Mobile Convergence (FMC). One of the features covered in that was ATSSS. It deserved a bit more detail so we made a short tutorial on this feature.

Access Traffic Steering, Switching and Splitting or ATSSS for short is being standardized as part of 3GPP Rel-16 and allows traffic steering across multiple accesses at a finer granularities than a PDU session.  It is an optional feature both on the UE and the 5GC network. ATSSS introduces the notion of Multi Access PDU session, a PDU session for which the data traffic can be served over one or more concurrent accesses (3GPP access, trusted non-3GPP access and untrusted non-3GPP access). The simplest way to visualize it is as shown below:


The presentation and video is embedded below:







Related Posts:

Sunday, 15 September 2019

Sunday, 21 April 2019

Wi-Fi 6 (a.k.a. 802.11ax) and other Wi-Fi enhancements

Last year I wrote about how Wi-Fi is getting new names. 802.11ax for example, the latest and greatest of the Wi-Fi standards is known as Wi-Fi 6. There were many announcements at MWC 2019 about WiFi 6, some of which I have captured here.

I came across a nice simple explanatory video explaining Wi-Fi 6 for non-technical people. Its embedded below.


The video is actually sponsored by Cisco and you can read more about Wi-Fi 6 and comparison of Wi-Fi 6 and 5G on their pages.

At MWC19, Cisco was showing Passpoint autoconnectivity on Samsung Galaxy S9, S9+ or Note 9 device. According to their blog:

Together, we’re working to provide a better bridge between mobile and Wi-Fi networks. At Mobile World Congress in Barcelona we’ll show the first step in that journey. Anyone using a Samsung Galaxy S9, S9+ or Note 9 device (and those lucky enough to have an early Galaxy S10) over the Cisco-powered guest wireless network will be able to seamlessly and securely connect – without any manual authentication. No portal, no typing in passwords, no picking SSIDs, no credit cards — just secure automatic connectivity.  How?  By using credentials already on your phone, like your operator SIM card.  Even if your operator doesn’t currently support Passpoint autoconnectivity, your Samsung smartphone will!  As a Samsung user, you already have an account for backups and device specific applications. This credential can also be used for a secure and seamless onboarding experience, supporting connectivity to enterprise, public and SP access networks.

It's worth mentioning here that the WPA2 authentication algorithm is being upgraded to WPA3 and we will see broad adoption this year, in conjunction with 802.11ax. See the tweet for details

Broadcom announced their new BCM43752, Dual-Band 802.11ax Wi-Fi/Bluetooth 5 Combo Chip. Motley Fool explains why this is interesting news:

The chip specialist is rounding out its Wi-Fi 6 portfolio to address lower price points.

When Samsung announced its Galaxy S10-series of premium smartphones, wireless chipmaker Broadcom announced, in tandem, that its latest BCM4375 Wi-Fi/Bluetooth connectivity combination chip is powering those new flagship smartphones. That chip was the company's first to support the latest Wi-Fi 6 standard, which promises significant performance improvements over previous-generation Wi-Fi technology.

The BCM4375 is a high-end part aimed at premium smartphones, meaning that it's designed for maximum performance, but its cost structure (as well as final selling price) is designed for pricier devices that can handle relatively pricey chips.

Broadcom explains that the BCM43752 "significantly reduces smartphone bill of materials by integrating [radio frequency] components such as power amplifiers (PAs) and low-noise amplifiers (LNAs) into the device."

The idea here is simple: Since these components are integrated in the chip that smartphone makers are buying from Broadcom, those smartphone makers won't need to buy those components separately.

In the press release, Broadcom quoted Phil Solis, research director at the market research company IDC, as saying that this chip "reduced costs by going down to single core, 2X2 MIMO for Wi-Fi, integrating the PAs and LNAs, and offering flexible packaging options while keeping the same functionality as their flagship combo chip." 

Broadcom explains that this chip is targeted at "the broader smartphone market where high performance and total solution cost are equally important design decisions."

In addition to these, Intel showed a demo of Wi-Fi 6 at 6GHz. Most people are aware that Wi-Fi uses 2.4 GHz, 5 GHz & 60 GHz band. According to Wi-Fi Now:

So why is that important? Simply because 6 GHz Wi-Fi is likely the biggest opportunity in Wi-Fi in a generation – and because Intel’s demo shows that Wi-Fi chipset vendors are ready to pounce on it. The demonstration was a part of Intel’s elaborate Wi-Fi 6 (802.11ax) demonstration set at MWC.

“When this enhancement [meaning 6 GHz spectrum] to Wi-Fi 6 rolls out in the next couple of years, it has the potential to more than double the Wi-Fi spectrum with up to 4x more 160 MHz channel deployment options,” said Doron Tal, Intel’s General Manager Wireless Infrastructure Group, in his blog here. Doron Tal emphasises that the prospect of including 6 GHz bands in Wi-Fi for the time being realistically only applies to the US market.

Intel also says that a growing number of currently available PCs already support 160 MHz channels, making them capable of operating at gigabit Wi-Fi speeds. This means that consumers will get ‘a pleasant surprise’ in terms of speed if they invest in a Wi-Fi 6 home router already now, Intel says.

It may however take a while before US regulator FCC finally rules on allowing Wi-Fi to operate in the 6 GHz bands. Right now the FCC is reviewing dozens of response submissions following the issuing of the NPRM for unlicensed 6 GHz operation – and they will likely have their hands full for months while answering a litany of questions as to prospective new 6 GHz spectrum rules.

Also an important part of the 6 GHz story is the fact that the IEEE only weeks ago decided that – as far as the 802.11 standards are concerned – only Wi-Fi 6 (802.11ax) will be specified to operate in the 6 GHz band. That means 6 GHz will be pristine legacy-free territory for Wi-Fi 6 devices.

That brings us to the Wi-Fi evolution that will be coming after 802.11ax. IEEE 802.11 Extremely High Throughput (EHT) Study Group was formed late last year that will be working on defining the new 802.11be (Wi-Fi 7?) standards. See tweet below:

The interesting thing to note here is that the Wi-Fi spectrum will become flexible to operate from 1 GHz to 7.125 GHz. Of course the rules will be different in different parts of the world. It will also have to avoid interference with other existing technologies like cellular, etc.

According to Fierce Wireless, Huawei has completed a global deployment of its enterprise-class Wi-Fi 6 products under the new AirEngine brand. Speaking at the company’s Global Analyst Summit, Huawei said its Wi-Fi 6 products have been deployed on a large scale in five major regions worldwide.

Back at MWC, Huawei was showing off their Wi-Fi 6 enabled CPEs. See tweet below:

Huawei has many different enterprise networking products that are already supporting Wi-Fi 6 today. You can see the details along with whitepapers and application notes here. In addition, the Top 10 Wi-Fi 6 misconceptions are worth a read, available here.

Related Posts

Friday, 12 April 2019

Slides from Parallel Wireless Webinar: 5G at #MWC19

I hosted a webinar for Parallel Wireless* yesterday about all the stuff related to 5G at Mobile World Congress 2019. The slides are embedded below and can be downloaded from BrightTalk here. You can also listen to the webinar there.




Related posts:



*Full Disclosure: I work for Parallel Wireless as a Senior Director in Strategic Marketing. This blog is maintained in my personal capacity and expresses my own views, not the views of my employer or anyone else. Anyone who knows me well would know this.

Monday, 8 October 2018

Wi-Fi gets new name


Wi-Fi Alliance has announced that the next generation WiFi technology, 802.11ax, will be known as Wi-Fi 6. This is to probably make it simpler, similar to mobile technology generations. Everyone knows 3G and 4G but how many people know UMTS or LTE. Similarly they are hoping that people will be aware of Wi-Fi 4, 5 & 6. They haven't bothered to name anything below Wi-Fi 4.


Looking at this picture from R&S above, you can see that according to Wi-Fi Alliance naming convention:

Wi-Fi 1: 802.11a (1999)
Wi-Fi 2: 802.11b (1999)
Wi-Fi 3: 802.11g (2003)
Wi-Fi 4: 802.11n (2009)
Wi-Fi 5: 802.11ac (2014)
Wi-Fi 6: 802.11ax (2019)

Anyway, I am not going in any technical details in this post but look for the really good links on this topic below.

To learn more about the naming of next-gen Wi-Fi, check this link.

Further reading:

Friday, 1 June 2018

An Alternative 5G for Rural Communities


I recently presented my personal vision of an alternative 5G for rural communities on behalf of Parallel Wireless at the IEEE 5G Summit in Glasgow. I believe that the next few years are going to be crucial for MNOs to decide if they want to cover the rural areas or just continue to focus on built-up areas.

In some cases it may not really be worthwhile for example for a smaller operator to build a cellular IoT network as the returns may not be worth the effort and investment.

I should mention that the caveat is that a lot of alternative 5G approach in my presentation depends on at least one of the satellite megaconstellations being successfully deployed and being fully operational. I am assuming a sensible pricing would be in place anyway as the satellite operators cant keep charging whatever they want for ever.

So here is my alternative 5G vision


Slides (and pictures) are available here for anyone interested. For my slides, jump to page 244. Quite a few other good presentations on 5G too.

An article in EE times summarises this IEEE 5G conference quite well. Available here.



Let me know your thoughts.

Tuesday, 1 May 2018

MAMS (Multi Access Management Services) at MEC integrating LTE and Wi-Fi networks

Came across Multi Access Management Services (MAMS) a few times recently so here is a quick short post on the topic. At present MAMS is under review in IETF and is being supported by Nokia, Intel, Broadcom, Huawei, AT&T, KT.

I heard about MAMS for the first time at a Small Cell Forum event in Mumbai, slides are here for this particular presentation from Nokia.

As you can see from the slide above, MAMS can optimise inter-working of different access domains, particularly at the Edge. A recent presentation from Nokia (here) on this topic provides much more detailed insight.

From the presentation:

        MAMS (Multi Access Management Services) is a framework for

-            Integrating different access network domains based on user plane (e.g. IP layer) interworking,

-            with ability to select access and core network paths independently

-            and user plane treatment based on traffic types

-            that can dynamically adapt to changing network conditions

-            based on negotiation between client and network
        The technical content is available as the following drafts*



-            MAMS User Plane Specification: https://tools.ietf.org/html/draft-zhu-intarea-mams-user-protocol-02




*Currently under review, Co-authors: Nokia, Intel, Broadcom, Huawei, AT&T, KT,

The slides provide much more details, including the different use cases (pic below) for integrating LTE and Wi-Fi at the Edge.


Here are the references for anyone wishing to look at this in more detail:

Friday, 29 September 2017

Smartphone Wi-Fi Analytics for Travel Route Optimisations

Transport for London (TFL), the local government body responsible for transport in London, which also runs the London Underground (known as Tubes) has been using smartphone Wi-Fi data to work out how people travel on the stations.

They did the trial and collected data in 2016 and have also openly talked about it (see this talk for example), they have now published their findings which is available here. One of the interesting findings for example is that 18 different routes taken by customers between King's Cross St Pancras and Waterloo - and many people don't use the shortest route changing Tube lines

Its interesting to think that because many people do not have their Wi-Fi switched on while outside and many others who put their phone in plane more while in the underground (no mobile coverage, in case you are wondering), this data is probably not as detailed as it could have been.

Nevertheless, there is a talk of bringing Mobile connectivity into the underground network. Once its there, the combination of data could be far more valuable.

Thursday, 20 July 2017

Second thoughts about LTE-U / LAA

Its been a while since I wrote about LTE-U / LAA on this blog. I have written a few posts on the small cells blog but they seem to be dated as well. For anyone needing a quick refresher on LTE-U / LAA, please head over to IoTforAll or ShareTechNote. This post is not about the technology per se but the overall ecosystem with LTE-U / LAA (and even Multefire) being part of that.

Lets recap the market status quickly. T-Mobile US has already got LTE-U active and LAA was tested recently. SK Telecom achieved 1Gbps in LAA trials with Ericsson. AT&T has decided to skip the non-standard LTE-U and go to standards based LAA. MTN & Huawei have trialled LAA for in-building in South Africa. All these sound good and inspires confidence in the technology however some observations are worrying me.


Couple of years back when LTE-U idea was conceived, followed by LAA, the 5GHz channels were relatively empty. Recently I have started to see that they are all filling up.

Any malls, hotels, service stations or even big buildings I go to, they all seem to be occupied. While supplemental downlink channels are 20MHz each, the Wi-Fi channels could be 20MHz, 40MHz, 80MHz or even 160MHz.

On many occasions I had to switch off my Wi-Fi as the speeds were so poor (due to high number of active users) and go back to using 4G. How will it impact the supplemental downlink in LTE-U / LAA? How will it impact the Wi-Fi users?

On my smartphone, most days I get 30/40Mbps download speeds and it works perfectly fine for all my needs. The only reason we would need higher speeds is to do tethering and use laptops for work, listen to music, play games or watch videos. Most people I know or work with dont require gigabit speeds at the moment.

Once a user that is receiving high speeds data on their device using LTE-U / LAA creates a Wi-Fi hotspot, it may use the same 5GHz channels as the ones that the network is using for supplemental downlink. How do you manage this interference? I am looking forward to discussions on technical fora where users will be asking why their download speeds fall as soon as they switch Wi-Fi hotspot on.

The fact is that in non-dense areas (rural, sub-urban or even general built-up areas), operators do not have to worry about the network being overloaded and can use their licensed spectrum. Nobody is planning to deploy LTE-U / LAA in these areas. In dense and ultra-dense areas, there are many users, many Wi-Fi access points, ad-hoc Wi-Fi networks and many other sources of interference. In theory LTE-U / LAA can help significantly but as there are many sources of interference,its uncertain if it would be a win-win for everyone or just more interference for everyone to deal with.

Further reading:

Saturday, 10 December 2016

Free Apps for Field Testing

People who follow me on Twitter may have often noticed I put photos when I am doing surveys, field testing, debugging, etc. In the good old days we often had to carry a lot of different kind of specialised test equipment to do basic measurements. Nowadays a lot of these can be done with the help of free apps on Android phones. The best tool that can provide a great amount of info is Qualcomm's QXDM but its really expensive.

Here are a few tools that I use. If you have one that I havent listed below, please add it in comments.


The screen shot shows the main tools along with my favourite, SpeedTest. While I agree that Speedtest is not the most reliable approach to speed of your connection, I think its the most standard one being used.


WiFi Analyzer is another great app that can be used at home and other locations where people complain about not getting good WiFi speeds. I have been at locations where the 2.4GHz is absolutely packed with APs. 5GHz is also getting busier, though there are still a lot of free channels.


G-NetTrack Lite is a great tool to keep track of the cells you have been visiting. In case you are driving this can collect a lot of valuable info. The paid version, G-NetTrack Pro can collect the info in form of a map that can be used for offline viewing with the help of Google Earth.


I use LTE Discovery mainly for finding the band I am currently camped on. It would be great if a tool can give the exact frequency and earfcn but the band is good enough too. I was once in a situation where I could see two different cells but they had the same PCI. Only after using this, I figured out they were on different bands.


Finally, Network Cell Info Lite gives neighbour cells which can often be useful. I am not sure of these are the neighbours from System Info or from Measurement Control messages sent by network or just something like Detected cells that the phone sees around.

Pind and IPConfig are other tools that can come handy sometimes.

Are there any other tools that you like? Please share using comments.

Free Apps for Field Testing - Part 2

Sunday, 16 October 2016

Inside 3GPP Release-13 - Whitepaper by 5G Americas


The following is from the 5G Americas press release:

The summary offers insight to the future of wireless broadband and how new requirements and technological goals will be achieved. The report updates Release 13 (Rel-13) features that are now completed at 3GPP and were not available at the time of the publication of a detailed 5G Americas report, Mobile Broadband Evolution Towards 5G: 3GPP Release 12 & Release 13 and Beyond in June 2015.
The 3GPP standards have many innovations remaining for LTE to create a foundation for 5G.  Rel-12, which was finalized in December 2014, contains a vast array of features for both LTE and HSPA+ that bring greater efficiency for networks and devices, as well as enable new applications and services. Many of the Rel-12 features were extended into Rel-13.  Rel-13, functionally frozen in December 2015 and completed in March 2016, continues to build on these technical capabilities while adding many robust new features.
Jim Seymour, Principal Engineer, Mobility CTO Group, Cisco and co-leader of the 5G Americas report explained, “3GPP Release 13 is just a peek behind the curtain for the unveiling of future innovations for LTE that will parallel the technical work at 3GPP on 5G. Both LTE and 5G will work together to form our connected future.”
The numerous features in the Rel-13 standards include the following for LTE-Advanced:
  • Active Antenna Systems (AAS), including beamforming, Multi-Input Multi-Output (MIMO) and Self-Organizing Network (SON) aspects
  • Enhanced signaling to support inter-site Coordinated Multi-Point Transmission and Reception (CoMP)
  • Carrier Aggregation (CA) enhancements to support up to 32 component carriers
  • Dual Connectivity (DC) enhancements to better support multi-vendor deployments with improved traffic steering
  • Improvements in Radio Access Network (RAN) sharing
  • Enhancements to Machine Type Communication (MTC)
  • Enhanced Proximity Services (ProSe)
Some of the standards work in Rel-13 related to spectrum efficiency include:                                                                                                                       
  • Licensed Assisted Access for LTE (LAA) in which LTE can be deployed in unlicensed spectrum
  • LTE Wireless Local Area Network (WLAN) Aggregation (LWA) where Wi-Fi can now be supported by a radio bearer and aggregated with an LTE radio bearer
  • Narrowband IoT (NB-IoT) where lower power wider coverage LTE carriers have been designed to support IoT applications
  • Downlink (DL) Multi-User Superposition Transmission (MUST) which is a new concept for transmitting more than one data layer to multiple users without time, frequency or spatial separation
“The vision for 5G is being clarified in each step of the 3GPP standards. To understand those steps, 5G Americas provides reports on the developments in this succinct, understandable format,” said Vicki Livingston, Head of Communications for the association.

The whitepaper as follows:



Related posts:

Monday, 26 September 2016

QoS in VoWiFi

Came across this presentation by Eir from last year's LTE Voice Summit.



As the summary of the above presentation says:
  • Turning on WMM (or WME) at access point provides significant protection for voice traffic against competing wireless data traffic
  • Turning on WMM at the client makes only a small difference where there are a small number of clients on the wireless LAN. This plus the “TCP Unfairness” problem means that it can be omitted.
  • All Home gateways support WMM but their firmware may need to be altered to prioritise on DSCP rather than layer two

As this Wikipedia entry explains:

Wireless Multimedia Extensions (WME), also known as Wi-Fi Multimedia (WMM), is a Wi-Fi Alliance interoperability certification, based on the IEEE 802.11e standard. It provides basic Quality of service (QoS) features to IEEE 802.11 networks. WMM prioritizes traffic according to four Access Categories (AC): voice (AC_VO), video (AC_VI), best effort (AC_BE), and background (AC_BK). However, it does not provide guaranteed throughput. It is suitable for well-defined applications that require QoS, such as Voice over IP (VoIP) on Wi-Fi phones (VoWLAN).

WMM replaces the Wi-Fi DCF distributed coordination function for CSMA/CA wireless frame transmission with Enhanced Distributed Coordination Function (EDCF). EDCF, according to version 1.1 of the WMM specifications by the Wi-Fi Alliance, defines Access Categories labels AC_VO, AC_VI, AC_BE, and AC_BK for the Enhanced Distributed Channel Access (EDCA) parameters that are used by a WMM-enabled station to control how long it sets its Transmission Opportunity (TXOP), according to the information transmitted by the access point to the station. It is implemented for wireless QoS between RF media.

This blog post describes how the QoS works in case of WMM.



Finally, this slide from Cisco shows how it will all fit together.

Further reading:

Tuesday, 4 August 2015

The Importance of License Exempt Frequency Bands


Some of you may be aware that I am also a Technical Programme Manager with the UK Spectrum Policy Forum. Recently we published a whitepaper that we had commissioned to Plum consulting on "Future use of Licence Exempt Radio Spectrum". It is an interested read not only for spectrum experts but also for people trying to understand the complex world of spectrum.

The report is very well written. Here are a few extracts in purple:

Licence exempt frequency bands are those that can be used by certain applications without the need for prior authorisation or an individual right of use. This does not mean that they are not subject to regulation – use must still comply with pre-defined technical rules to minimise the risk of interference. Most licence exempt bands are harmonised throughout Europe and are shared with other services or applications, such as radars or industrial, scientific and medical (ISM) equipment. Wi-Fi and Bluetooth are probably the most familiar examples of mass-market licence exempt wireless applications, but the bands support many other consumer devices, such as cordless phones, doorbells, car key fobs, central heating controllers, baby monitors and intruder alarms. Looking to the future, licence exempt bands are likely to be a key enabler of wireless machine to machine (M2M) communication applications.

Key benefits of licence exempt bands include:
  • For end-users:
    • Greater convenience and flexibility by avoiding the need for lengthy runs of cable in home and work environments
    • Ability to connect mobile devices to a fixed broadband network, reducing dependence on the mobile network and potentially saving costs both for the service provider and the end-user
    • Enhanced convenience, safety and security, e.g. through installation of low cost wireless alarm systems or ability to unlock vehicles remotely rather than fumbling with keys
  • For equipment vendors and operators:
    • Facilitating market entry – there is no need to acquire a licence to deploy a service
    • Enabling niche applications or services to be addressed quickly and cheaply using existing technology and spectrum – this has been particularly effective in serving new machine to machine (M2M) applications in areas such as health, transport and home automation.
    • Providing certainty about spectrum access – there is no need to compete or pay for spectrum access (though the collective nature of spectrum use means quality of service cannot be guaranteed)
    • The ability to extend the reach of fixed communication networks, by providing wireless local area connectivity in homes, businesses and at public traffic hotspots.
The two most notable drawbacks are the inability to guarantee quality of service and the more limited geographic range that is typically available (reflecting the lower power limits that apply to these bands). Licence exempt wireless applications cannot claim protection from interference arising from other users or radio services. They operate in shared frequency bands and must not themselves cause harmful interference to other radio services.

From a regulator’s perspective, licence exempt bands can be more problematic than licensed bands in terms of refarming spectrum, since it is difficult to prevent the continued deployment of legacy equipment in the bands or to monitor effectively their utilisation. There is also generally no control over numbers and / or location of devices, which can make sharing difficult and limits the amount of spectrum that can be used in this way.

In Europe, regulation of licence exempt bands is primarily dealt with at an international level by European institutions. Most bands are fully harmonised, whereby free circulation of devices that comply with the relevant standards is effectively mandated throughout the EU. However some bands are subject to “soft” harmonisation, where the frequency limits and technical characteristics are harmonised but adoption of the band is left to national administrations to decide.

A key recommendation, which I think would be very interesting and useful would be: Promote further international harmonisation of licence exempt bands, in particular the recently identified 870 – 876 MHz and 915 – 921 MHz band that are likely to be critical for supporting future M2M demand growth in Europe.

Note that a similar sub-1GHz band has been recommended for 5G for M2M/IoT. The advantage for low frequencies is that the coverage area is very large, suitable for devices with low date rates. Depending on how the final 5G would be positioned, it may well use the license exempt bands, similar to the LAA/LTE-U kind of approach maybe.

The whitepaper is embedded below and is available to download from here: