4.5G: Integration of LTE and Wi-Fi networks

With LTE-A getting ready to meet the IMT-Advanced requirements and fulfilling the role of promised '4G', we believe the next phase of evolution before 5G will be successful interworking of LTE and Wi-Fi networks.

This whitepaper (embedded below) explores this feature, we call 4.5G, in detail.



We are very thankful to Anritsu for kindly sponsoring this whitepaper. They have their own whitepaper on this topic which is also worth a read, available here.

4.5G: Integration of LTE and Wi-Fi networks from eXplanoTech

Let us know what you think about this.

Mobile Video Offload using Wi-Fi is the only solution in the coming years

A very interesting infographic from Skyfire some months back highlighted some very valid issues about Video on mobiles.

Personally, I do watch quite a bit of video on my phone and tablet but only when connected using Wi-Fi. Occasionally when I am out, if someone sends me video clip on Whatsapp or some link to watch Video on youtube, I do try and see it. Most of the time the quality is too disappointing. It could be because my operator has been rated as the worst operator in UK. Anyway, as the infographic above suggests, there needs to be some kind of an optimisation done to make sure that end users are happy. OR, the users cn offload to Wi-Fi when possible to get a better experience.

This is one of the main reasons why operators are actively considering offloading to Wi-Fi and have carrier WiFi solutions in place. The standards are actively working in the same direction. Two of my recent posts on the topic of 'roaming using ANDSF' and 'challenges with seamless cellular/Wi-Fi handover' have been quite popular.

Recently I attended a webinar on the topic of 'Video Offload'. While the webinar reinforced my beliefs about why offload should be done, it did teach me a thing or two (like when is a Hotspot called a Homespot - see here). The presentation and the Video is embedded below. Before that, I want to show the result of a poll conducted during the webinar where the people present (and I would imagine there were quite a few people) were asked about how they think MNO will approach the WiFi solution in their network. Result as follows:

Here is the presentation:

Video Offload -Six trends you NEED to understand! from Zahid Ghadialy

Here is the video of the event:

SIPTO Evolution

Couple of years back I did a post on SIPTO (Selected IP Traffic Offload) and related technologies coming as part of Rel-10. I also put up a comparison for SIPTO, LIPA and IFOM here. Having left it for couple of years, I found that there have been some enhancements to the architecture from the basic one described here.

I have embedded the NEC paper below for someone wanting to investigate further the different options shown in the picture above. I think that even though the operator may offload certain type of traffic locally, they would still consider that data as part of the bundle and would like to charge for it. At the same time there would be a requirement on the operator for lawful interception, so not sure how this will be managed for different architectures. Anyway, feel free to leave comments if you have any additional info.

NEC: Mobile Traffic Offload from Zahid Ghadialy

Key challenges with automatic Wi-Fi / Cellular handover

Recently in a conference I mentioned that the 3GPP standards are working on standards that will allow automatic and seamless handovers between Cellular and Wi-Fi. At the same time operators may want to have a control where they can automatically switch on a users Wi-Fi radio (if switched off) and offload to Wi-Fi whenever possible. It upset quite a few people who were reasoning against the problems this could cause and the issues that need to be solved.

I have been meaning to list the possible issues which could be present in this scenario of automatically handing over between Wi-Fi and cellular, luckily I found that they have been listed very well in the recent 4G Americas whitepaper. The whitepaper is embedded below but here are the issues I had been wanting to discuss:

In particular, many of the challenges facing Wi-Fi/Cellular integration have to do with realizing a complete intelligent network selection solution that allows operators to steer traffic in a manner that maximizes user experience and addresses some of the challenges at the boundaries between RATs (2G, 3G, LTE and Wi-Fi).
Figure 1 (see above) below illustrates four of the key challenges at the Wi-Fi/Cellular boundary.
1) Premature Wi-Fi Selection: As devices with Wi-Fi enabled move into Wi-Fi coverage, they reselect to Wi-Fi without comparative evaluation of existing cellular and incoming Wi-Fi capabilities. This can result in degradation of end user experience due to premature reselection to Wi-Fi. Real time throughput based traffic steering can be used to mitigate this.
2) Unhealthy choices: In a mixed wireless network of LTE, HSPA and Wi-Fi, reselection may occur to a strong Wi-Fi network, which is under heavy load. The resulting ‘unhealthy’ choice results in a degradation of end user experience as performance on the cell edge of a lightly loaded cellular network may be superior to performance close to a heavily loaded Wi-Fi AP. Real time load based traffic steering can be used to mitigate this.
3) Lower capabilities: In some cases, reselection to a strong Wi-Fi AP may result in reduced performance (e.g. if the Wi-Fi AP is served by lower bandwidth in the backhaul than the cellular base station presently serving the device). Evaluation of criteria beyond wireless capabilities prior to access selection can be used to mitigate this.
4) Ping-Pong: This is an example of reduced end user experience due to ping-ponging between Wi-Fi and cellular accesses. This could be a result of premature Wi-Fi selection and mobility in a cellular environment with signal strengths very similar in both access types. Hysteresis concepts used in access selection similar to cellular IRAT, applied between Wi-Fi and cellular accesses can be used to mitigate this.

Here is the paper:

Integration of Cellular and Wi-Fi Networks from Zahid Ghadialy

802.11u, Passpoint and Hotspot 2.0 (HS 2.0)

Came across this interesting Video on Youtube explaining 802.11u that is embedded below.




A bit more detailed presentation on the same topic by Ruckus is also embedded below:


Related posts:

• Wi-Fi & Packet Core (EPC) Integration
• Hotspot 2.0, Next Generation Hotspot (NGH), etc.
• Cellular-Wi-Fi Integration - technology and standardization roadmap

Wi-Fi & Packet Core (EPC) Integration

Yesterday I wrote a blog post on whether Wi-Fi is the third RAN in the Metrocells blog. Today I am posting this excellent presentation that details how this Wi-Fi integration with EPC will be done.

Wi-Fi & packet core integration from Zahid Ghadialy

Four Options for Traffic Offloading

A Twitter discussion on 'Data Tsunami' myth

Participants:


@disruptivedean - Dean Bubley
@StevenJCrowley - Steve Crowley
@WhatTheBit - Stefan Constantine
@labboudles - Leila Abboud
@twehmeier - Thomas Wehmeier
@jamncl4 - Jonathan Morgan
@wifidave - Dave Wright

@disruptivedean: Data tsunami myth washing further out to sea: Telefonica mobile data grew 35% YoY to Q1, vs. data rev growth of 28%. http://www.telefonica.com/en/shareholders_investors/html/financyreg/resultados2012.shtml


@disruptivedean: Increasingly convinced that some cellular data growth numbers & forecasts are over-inflated - mainly to sway regulators on spectrum policy

@StevenJCrowley: Wonder how much of Telefonica lower data growth is from Spain's unusually bad economy versus normal "S curve"

@twehmeier: Did you see that shockingly unbalanced story on data traffic in FT? Pure spin. Telefonica is v representative of Euro ops. The other factor is vendors perpetuating the myth to sell their products and services

@WhatTheBit: you should do some research into operator spectrum holdings versus actual utilization, I'm sure the results would B shocking

@twehmeier: The other factor is vendors perpetuating the myth to sell their products and services

@disruptivedean: Don't think Spanish economy that much an issue. Growth been flattening in UK & Germany for a while - http://disruptivewireless.blogspot.co.uk/2011/11/smoking-gun-i-think-o2-uk-has-falling.html


@disruptivedean: The contrast in attitude between TF corporate vs. TF Digital is striking sometimes.

@labboudles: that's interesting, is it typical of others ops numbers, ie data makes them money so stop whining abt capex/google?

@disruptivedean: It's certainly true for VF in Europe - they have faster data rev growth than traffic growth. Caps/tiers fixed the problem


@disruptivedean: Basic pricing tiers/caps + user-controlled WiFi have "fixed" the problem. Has undermined need for more complex solutions & tech

@twehmeier: Indeed. amazes me how little emphasis placed on imprtnce of pricing. Next prob will be working out how to bring traffic back

@disruptivedean: Yes, especially with LTE - in some places/networks we're heading for overcapacity. Not quite as bad as fibre in 2001, but scary

@twehmeier: And that will likely lead to more naive pricing models that only serve to accelerate self-commoditisation of value of data!


@twehmeier: Telenor firsy reported faster data revenue growth versus traffic back in 2010. And that's in some of the world's most advanced smartphone and MBB markets...

@labboudles: thought so since that was case in France, but admit had not looked at all ops trends

@disruptivedean: Also beware that some operators (eg AT&T) have started adding in WiFi hotspot traffic to bump up the numbers

@twehmeier: Shameless lobbying....

@labboudles: where is there overcapacity?! Places where LTE has been built and already used?

@twehmeier: imagine a market where Wi-Fi is ubiquitous and all operators deploy LTE on top of pre-existing HSPA/HSPA+. And remember average utilisation of European 3G networks is typically only in the 35-40% range and pretty steady

@labboudles: that's a ways off in real world though


@labboudles: ok that I just don't understand, then why is my user experience of mobile Internet so crap n London, Paris ?

@disruptivedean: Depends how you calculate it. Bear in mind many MNOs don't "light up" all spectrum initially, but add extra capacity


@disruptivedean: Plenty of other bottlenecks - most notable is poor coverage, could be backhaul, stuff in core network, even DNS etc


@disruptivedean: Congestion often caused by too much signalling (setting up/tearing down IP conxns), not sheer data "tonnage"

@jamncl4: Actually I think we are also seeing the impact of the shift from laptops to tablets and smartphones


@jamncl4: People can't afford multiple data plans so they shift from laptop to Smartphones which inherently use less data

@wifidave: How did you arrive at 35%/28%? I found 15.4% YoY in "mobile data revenue", and couldn't find traffic figures.

@jamncl4: Same with tablets which also pull usage away from laptop except most tablets are wifi only


@jamncl4: WiFi is in enough places that I can't justify two data plans so I stick to wifi tablet and data pla smartphone

@disruptivedean: It's on page 6 of the results presentation, showing rapid convergence of traffic & revenue growth

@jamncl4: The smartphone will take a few years to catch up to laptops in terms of data requirements thus "slowdown" growth

@disruptivedean: Bear in mind rising % of people don't have "plans" but use PAYG for data. But yes, dongle traffic falling, phone rising

@jamncl4: But Smartphone require higher signaling than laptops due to apps & power saving techniques;massive signal growth

@disruptivedean: Tablet/laptop substitution (or not) largely irrelevant as both are generally WiFi-only & will most likely stay that way

@jamncl4: Multi device plans could be interesting moving forward and there impact on this


@jamncl4: I disagree. Majority of traffic has come from laptops in past so more wifi & tablets reduces the traffic

@wifidave: @disruptivedean OK, I see. The 27% is a subset of the 15.4%.

@jamncl4: I think the real issue is that people don't want to pay for 2 plans & the 1 plan in general is Smartphone for now. Multidevice PAYG plans will be interesting on their impact.

@wifidave: Ponder this > Assuming TF #s are cell data, they represent a mobile data Traffic/Rev YoY growth ratio of 1.29:1 . The same ratio for #ChinaMobile in Q4'11 was 1.28:1 . For #ChinaMobile, cell data grew at 56.1% traffic and 43.5% revenues.


@wifidave: ATT says that "wireless data traffic" doubled in 2011 from 2010. (http://www.attinnovationspace.com/innovation/story/a7781181). but elsewhere report that their Wi-Fi traffic increased 550% in Q4'11. (http://www.vision2mobile.com/news/2012/01/wif.aspx). all while wireless data revenues only grew 19.4% YoY in Q4'11 (http://www.att.com/gen/press-room?pid=22304&cdvn=news&newsarticleid=33762)


@wifidave: The real growth (337% and 550% for CM and ATT) is in Wi-Fi as Dean said. Not adding much to rev yet.

@disruptivedean: Absolutely agree more WiFi = less "big device mobile data traffic". Unconvinced it matters if big device = laptop/tablet


----------------------x------------------------o---------------------------x------------------------

3 Stages for Seamless Mobility between 3G and WLAN

Capacity planning in mobile data networks experiencing exponential growth in demand

Key note presentation by Dr. Kim Larsen at Informa’s 3G, HSPA & LTE Optimization conference in Prague.

You can follow the complete discussion on Twitter using tag #ITMoptimisation

Capacity planning in mobile data networks experiencing exponential growth in demand from Dr. Kim (Kyllesbech Larsen)

Related Post:

• Summary of tweets from #ITMoptimisation

Discussion on 'Offload' and 'Onload'

An interesting discussion on Twitter about Offload and Onload that is reproduced below. Discussions have been edited for clarity:


@StevenJCrowley: Exhibit 1: In last year's VNI, Cisco estimated that in 2014, 23% of US mobile data would be offloaded. It's close to 50% today.


@dmavrakis: it depends how you define offload. Some of this 50% may be simple WiFi access rather than offload.

@StevenJCrowley: From what I see I'd suggest Wi-Fi (or femto) access is offload if the device is 2,3,4G capable but does not access a macrocell


@dmavrakis: So if I buy a SIM-only handset and not even put a SIM in and use WiFi, it's considered offload?


@StevenJCrowley: Seems to me that's not considered offload because without a SIM it's not a 2,3,4G capable device.


@StevenJCrowley: BTW my old AT&T iPhone 3G won't work as a Wi-Fi-only device without an old inactive SIM still in it. Don't know about iPhone 4.


@disruptivedean: I agree with @dmavrakis . Most smartphone WiFi use if "private WiFi", not offload. Some may even be onload (or "OTT WiFi")

@disruptivedean: Easy way to think of it: anything you'd do on an iPod Touch isn't offload WiFi if you do the same thing on iPhone


@disruptivedean: Other example: if I use WiFi to connect my phone to my printer (or corp WLAN) = traffic never destined for 2G/3G


@simonchapman: app downloads (500MB+ for some games), AirPlay etc are much greater than 2/3/4G use. Where is 50% figure from? 


@SteveLightley: the actual presence of decent connectivity encourages higher capacity activity. Is that offload?


@disruptivedean: I refer to extra use as "elastic". See chart on p18 of my Carrier WiFi paper http://www.scribd.com/doc/61910980/Disruptive-Analysis-Carrier-WiFi


@StevenJCrowley: Decent connectivity / more use is offload, as 3G4G w/o Wi-Fi is onload. U.S./FCC/Cisco perspective


@StevenJCrowley: I define "onload" as a 2nd operator capturing traffic via WiFi, eg Vodafone handset + O2 WiFi app


@dmavrakis: Also core network onload via WLAN gateways without local breakout.


@disruptivedean: A thought about "offload". I only "onloaded" to 3G data on my PC in the first place because WiFi wasn't everywhere I needed it. Now it is.


@StevenJCrowley: 50% rough estimate. AT&T said 40% of iPhone traffic on Wi-Fi in early 2010. Its Wi-Fi network data tripled since


@StevenJCrowley: Does not include femto offload. See also "#2" from this blog post bit.ly/wxHvRl


@StevenJCrowley: AT&T recently said macrocell data growth down to 40% a year.


@StevenJCrowley: I like Dean's chart. Offloading important in U.S. from 4G spectrum requirements issue.


@StevenJCrowley: And here spectrum debate is more political than technical, thus broad brushes.


@StevenJCrowley: It's basically, "We need spectrum to stream NetFlix." "No, you're inside and can use Wi-Fi."


@StevenJCrowley: Dean's and Ofcom's analyses are the types of things current FCC should be doing but doesn't


@disruptivedean: The whole spectrum reqts issue likely to take a hit as data growth << expected on many networks. S-curve not exponential


@disruptivedean: To be fair, Cisco is between a rock & a hard place with VNI. Scared people into making sure it didn't come true. Self-denying


@Gabeuk: To everyone discussing offload on my Twitter today, the premise seems wrong... connectivity & access is the start point. Will elaborate l8er


@SteveLightley: I struggle to understand how if it would never have happened how it can be classed as offloaded


@SteveLightley: a VoIP call on an ott or mno app IS offload but Netflix in Starbucks over wifi is not


@SteveLightley: looking forward to gabe's view on access etc when he gets here! 


@TMFAssociates: AT&T seems to have changed its tune over the last year as well http://gigaom.com/broadband/atts-vanishing-spectrum-crisis/


@StevenJCrowley: AT&T will spin it. "If only we had more spectrum we could have sent more data." Etc.


@dmavrakis: Arguably spectrum is the MNO's most valuable possession. Isn't it natural that they want more?


@StevenJCrowley: More spectrum than needed is an idle asset that costs the company money.


@TMFAssociates: But if you corner the market then you can foreclose the possibility of competition


@dmavrakis: I agree conditionally. Twitter is again not the best medium for this discussion

Couple of interesting posts related to the above:

• Watch out for dodgy offload & optimisation claims and stats - Dean Bubley (@disruptivedean)
• What to make of AT&T’s vanishing spectrum crisis

What is your opinion?