Roadmap of wifi: For coming years...

Is wifi saturated? whats coming up in wifi world?
Lately, i have been hearing this question a lot and decided to find an answer.

I believe that the field of wifi is very busy in the coming years, technology wise not so much change, the basic protocol remains same and so are the basic rules, but its more user-centric now and more real world scenario based. Lets take a look at the things coming up and soon in wifi

Lets divide the upcoming things in wifi in to technology based and user based.This time less text and more crisp no detailed technical analysis :-) , because most of these things have a roadmap of around 2015-2016, many of the TG's are in the nascent state.

Technology Centric: IEEE			User Centric: WFA
802.11 ac	PHY Changes	256 QAM, MU-MIMO, Beamforming, BW signalling,	Wifi Miracast	On top of P2P based Sharing ending Video and Audio over wifi, eg: project your video from laptop to TV
802.11aq	MAC Changes	Low Power Pre-association discovery	Neighbour aware networking	On top of P2P with Low power pre-association discovery and Information sharing, Get a pop up if the information matches then proceed through normal connection (P2P/AP)
802.11ah	PHY Changes	sub 1GHz < 1GHz (excluding TV) spectrum and 1,2,4,8,16 MHz bandwidths, over 1KM distances and 300 Kbps Low Power Large STA association Improvised legacy Powersave	Wifi Docking	P2P based Connecting Multiple peripheral using wifi
802.11ad	PHY Changes	Gigabit Wifi, 60 GHz Unlicensed	WNM Powersave	Max Idle Periods, Proxy ARP, WoW, Convert Multicast to Unicast (Direct/Flexible)
802.11af	PHY Changes	Wifi TV: SUB 1GHz TV band Optional AC for spectrum sense	Wifi Smart Grid	Smart Energy Profiles 2.0 compatible with non-wifi as well eg. Zigbee.
802.11ae	MAC Changes	Prioritization of Management frames
802.11ai	MAC Changes	Fast initial link setup: < 100ms data connection Lesser Management Frames

In short, we have got all the three tracks covered IEEE is working on huge

                     Major PHY changes : 

• Spectrum     : 3.7GHz, sub 1GHz, 60GHz
• Bandwidth   : 1, 2,4,8 and 16 MHz
• Low power   : Energey Efficient
• FSN OFDM : 64 subcarriers (Fixed Subcarrier Number)

                    Minor MAC changes 

• All advanced WFA programs are P2P based.
• Fast Discovery
• Fast Connection, 
• Efficient and Long powersave, 
• QoS for Management,

where as WFA is working on IOT and End-User scenarios and applications.

So for coming 5 years i would say wifi has lots of work to do. Especially the standard 802.11ah and ad are very popular among engineers and companies and are highest attended TG's.

Any more new ideas/use cases for wifi ? Please share your opinion.

802.11 WMM Priorities: UP/TID/802.1D Demystified.

WMM introduces the concept of priority in to wlan, but to implement the priority it uses a complex terminology like UP (User Priority), TID (Traffic ID)  and  802.1D priority. 

All seem to represent the same "priority" and convey the same information, but then why do we need the three different terms. This confuses many, especially in TSPEC/TCLAS we see TID and UP both in the same frame leading to more confusion. Lets take a quick glance at what they mean and when should we use each of them.

We know that priority in WLAN is tightly coupled with the priority set by the application in the upper layers, so first we need to understand the LLC and MAC interface i.e., MAC SAP.

MA-UNITDATA.request is the primitive used to send any MSDU's to MAC by LLC, in this request the params used are

• source address,
• destination address,
• routing information,
• data,
• priority,
• service class

Here Priority can be an integer from 0-15 (or) non-integer of "contention"/"contention-free".

TX SIDE:

Integer Priority: 

Values:
             0-7 for QOS STA's in an QOS IBSS
             0-15 for QOS STA's in an QOS BSS

The priority directly maps to TID field identify the particular traffic stream from LLC. TID is not priority, its just an ID through which the actual priority is derived....

if (0 <= TID <8)
       UP=TID
else if (8<= TID <=15)
     if (TSPEC defined)
              UP= TID from TSPEC/TCLAS
    else
             UP = 0

Non-Integer Priority:

• At QoS STAs associated in a QoS BSS, MSDUs with a priority of Contention are considered equivalent to MSDUs with TID 0
• and those with a priority of ContentionFree are delivered using the contention-free delivery if a point coordinator (PC) is present in the AP. 
• If a PC is not present, MSDUs with a priority of ContentionFree shall be delivered using an UP of 0

• At STAs associated in a non-QoS BSS, all MSDUs with an integer priority are considered equivalent to MSDUs with a priority of Contention.

RX SIDE:

If a STA is associated in a QoS BSS, the MSDUs it receives in QoS data frames are reported with the TID
value contained in the MAC header of that frame.

 The MSDUs such a STA receives in non-QoS data frames
are reported to LLC with a priority of Contention, if they are received during the CP, 

or ContentionFree, if they are received during the CFP.

Summary:

TID: 4 bits ID Used in

        QOS CTRL Header

               EDCA: same as UP (0-7)

               HCCA: TSID (8-15)

        TSPEC/TCLAS

UP: 3 bits Priority

        TSPEC/TCLAS

802.1D: 3 bits
          Used Internally similar to UP, taken from the bridging standard.