Showing posts with label Broadband. Show all posts
Showing posts with label Broadband. Show all posts

Sunday, 21 June 2015

Broadband Access via Integrated Terrestrial & Satellite Systems

Last week I attended an event in the University of Surrey that was about providing high speed connectivity to un-served and under-served areas in future. While there is no arguing that satellites are a great option for unserved areas, the underserved areas can really benefit by such initiatives.

The way this is being proposed is to have a specialised Intelligent User Gateway (IUG) that can connect to ADSL, Mobile and Satellite. The assumption is that in areas of poor conectivity, ADSL can provide 2Mbps and the mobile could do something similar, upto 8Mbps. The satellites can easily do 20Mbps.

While the satellite broadband has the advantage of high speeds, they often suffer from high latencies. ADSL on the other hand has very small latency but may not be good enough for streaming kind of applications. Mobile generally falls in between for latency and speed. Using Multipath TCP and some intelligent routing algorithms, decisions can be taken to optimise for latency and speeds.

I did see some impressive demo's in the lab and it did what is says on the tin. The real challenge would be the business models. While ADSL can offer unlimited internet, both Mobile and Satellite broadband will have caps. I was told that limits could be imposed so that once the Mobile/Satellite data allowance is over, only ADSL would be used. Maybe a more complex algorithm could be implemented in future that can include cost and priority of the application/service being used.

An example would be that sometimes I want to watch some long videos over Youtube but I am happy to start buffering an hour in advance. Its not critical that I have to watch that now. I would be more than happy to save my Mobile/Satellite broadband data allowance for some other day when I need to watch things more urgently. If the end of month is coming and I have a lot of data allowance left then maybe I dont mind using the quota otherwise I will anyway lose the allowance. Its always challenging to put this intelligence in the routing decision algorithms though.

Anyway, the combined presentations are embedded below and you can download them from the BATS project page here:

Sunday, 15 March 2015

Air-Ground-Air communications in Mission Critical scenarios

In-flight communications have always fascinated me. While earlier the only possibility was to use Satellites, a hot topic for in the last few years has been Air-Ground-Air communications.

Some of you may remember that couple of years back Ericsson showed an example of using LTE in extreme conditions. The video below shows that LTE can work in these scenarios.

Now there are various acronyms being used for these type of communications but the one most commonly used is Direct-Air-to-Ground Communications (DA2GC), Air-to-Ground (A2G) and Ground-to-Air (G2A).

While for short distance communications, LTE or any cellular technology (see my post on Flying Small Cells) may be a good option, a complete solution including communication over sea would require satellite connectivity as well. As I have mentioned in a blog post before, 75Mbps connectivity would soon be possible with satellites.

For those interested in working of the Air-Ground-Air communications, would find the presentation below useful. A much detailed ECC CEPT report from last year is available here.

The next challenge is to explore whether LTE can be used for Mission Critical Air Ground Air communications. 3GPP TSG RAN recently conducted study on the feasibility and the conclusions are as follows:

There is a common understanding from companies interested in the topic that:

  1. Air-to-Ground communications can be provided using the LTE standards (rel-8 and beyond depending on the targeted scenarios).
  2. 3GPP UE RF requirements might need to be adapted
  3. It may be possible to enhance the performance of the communications with some standards changes, but these are in most cases expected to be non-fundamental optimizations
  4. Engineering and implementation adaptations are required depending on the deployment scenario. In particular, the ECC report [1] comments that from implementation point of view synchronization algorithms are to be modified compared to terrestrial mobile radio usage in order to cope with high Doppler frequency shift of the targeted scenario. In addition, some network management adaptations might be needed. From engineering perspective the Ground base station antenna adjustment has to be matched to cover indicated aircraft heights above ground up to 12 km by antenna up-tilt. It is also expected that the inter-site distances would be dominated by the altitudes to be supported [5].
  5. A2G technology using legacy LTE has been studied and successfully trialed covering different kinds of services: Surfing, downloading, e-mail transmission, use of Skype video, audio applications and Video conferencing. Related results can be found in several documents from ECC and from companies [1], [2], [3]. The trials in [1] and [2] assumed in general a dedicated spectrum, and the fact that the communications in the aircraft cabin are using WIFI or GSMOBA standards, while LTE is used for the Broadband Direct-Air-to-Ground connection between the Aircraft station and the Ground base station.
  6. It is understood that it is possible to operate A2G communications over spectrum that is shared with ground communications. However, due to interference it is expected that the ground communications would suffer from capacity losses depending on the deployment scenario. Therefore, it is recommended to operate A2G communication over a dedicated spectrum.
  7. It can be noted that ETSI studies concluded that Spectrum above 6 GHz is not appropriate for such applications [4].
  8. LTE already provides solutions to allow seamless mobility in between cells. Cells can be intended for terrestrial UEs and cells intended for A2G UEs which might operate in different frequencies.
  9. Cell range in LTE is limited by the maximum timing advance (around 100km). Larger ranges could be made possible by means of implementation adaptations. 

Saturday, 23 November 2013

Bandwidth is not the answer – it’s stationarity

Martin Geddes did an interesting presentation in Future of Broadband workshop. The ITU has the following write-up on that workshop

Eye-opening, evangelical and extremely well attended: this afternoon’s Future of Broadband workshop was all about exploding established concepts on how telcos should go about improving both customer experience and their bottom line.
Ranking broadband in terms of speed is the standard approach, but speed is not the only thing that matters in this business, according to Martin Geddes of Geddes Consulting, running the workshop in conjunction with Neill Davies of Predictable Network Solutions.  He illustrated his point with a series of examples drawn from customers accessing broadband at different speeds – but with unexpectedly different experiences.
Slower broadband, whether over cable, satellite or fibre, in many cases offered a better quality of customer experience than the faster variant. Why? Variability, or rather lack of variability, is the key. A stable service, even it is slower, enables POTS-quality VoiP, whereas a highly-variable, faster service delivers a less satisfactory customer experience – and, by definition, an unhappier customer.
“The hidden secret of networking is that the network delivers loss and delay between packets,” said Geddes, “There is more to broadband than speed or capacity: with many customers wanting lots of different things at once, we also need an absence of variability, and that is what we call stationarity.”
Looked at from the network operator side, there are two key areas to consider: what is driving the cost of broadband and pushing capex sky high, and how to retain and increase your customer base to bring in the revenue. The answers, it seems, are not immediately obvious.
To start with, the knee-jerk telco reaction of pouring capex into infrastructure upgrades and increased capacity is simply not the way to ensure good quality of service and happy customers.  Demand for broadband is highly elastic, expanding to consume whatever supply is on offer and creating a “jack-hammer effect” – which produces variability. Paradoxically, increased investment in bandwidth may be behind that very poor service which leads to customer churn and the panicked assumption that another upgrade is necessary – an “investment cycle of doom.”
This is a deep systemic problem in the industry investment machine. Rushing to premature upgrades masks the real core issue, that of quality of service.  The presenters demonstrated this in heaven-hell model, where full network capacity and happy customers is telco heaven – and the converse, unhappy customers and underused network, is of course telco hell.  Getting the balance is not easy, as increasing local networks pushes down the quality of experience for applications with strong stationarity requirements – exactly what the customer is after.
For Martin, there is a tiny root cause of this: all current packet-based infrastructure relies on it being idle and keeping queues empty to ensure good quality. So your assets must stay idle to keep your customer. The solution lies in thinking about how to reframe both this problem, and the exact nature of the resource the operators are selling.
“Don’t make packets move for their own sake, but focus on customer experience. Change the resource model,” urged Martin. “Throw away the bandwidth model and thought process.” Efficiently allocating resources to customers is more important than bandwidth. Increase capacity, but only in a very targeted way.  In other words, meet heterogeneous  demand with a differentiated product.
This, then, is how to ensure a future of broadband heaven: understand that quality of experience is a function of loss and delay. Characterize your supply requirements properly. Work out what customers are after, certifying fitness of purpose for a particular, actual customer demand rather than a generalised one-size-fits-all concept. And, in the words of the workshop presenters: “Don’t sell bandwidth – sell differential experiences.”

His presentation is embedded as follows:

Wednesday, 11 April 2012

Whitespace Spectrum Management Issues

BT has been conducting a "White Space" trial in Isle of Bute, UK. Initial report suggests that the results are not very impressive. The following is from ISP Review:

Early feedback from BT’s trial of ‘White Space‘ (IEEE 802.22) wireless broadband technology on the Isle of Bute suggests that the service, which delivers internet access by making use of the unused radio spectrum that exists between Digital TV channels, still has a lot of problems to overcome, not least in terms of its sporadic performance.

In theory the 802.22 specification suggests that download speeds of up to 22Mbps per channel (Megabits per second) could be possible and some UK trials claim to have reached around 16Mbps, which is incidentally a long way off the UK’s chosen definition for superfast broadband (24Mbps+).
But separate reports from both PC Pro and the BBC today found that the service, which is complicated to deliver due to the ever changing spectrum and the risk of causing interference to DTV services, could struggle to deliver its top speeds.

At present BT’s implementation claims to be offering speeds of up to 10Mbps per channel, which will soon be upgraded to 15Mbps, but this reduces down to a maximum of just 4Mbps when 6km away from the transmitter. New tests at various points on the Isle of Bute showed speeds varying between just 1.5Mbps and 6Mbps (the latter was recorded within sight of BT’s mast).
In fairness White Space solutions are designed to target the last 10% of the UK where the government has so far only committed to a minimum download speed of just 2Mbps for all (Universal Service Commitment), which is a very low target. In addition White Space tech appears to deliver strong upload speed that is, in some cases, symmetrical. That makes it good for video conferencing and other upload dependent tasks.

As Fierce Broadband Wireless suggests, the low speeds could also be due to pre-standard gear that will just improve as time goes on.

The main reason for using this shared whitespace spectrum is due to the fact that the total amount of spectrum is limited and we want to make use of every available free spectrum to increase capacity of the overloaded networks.

Michael Fitch from BT recently spoke in our Cambridge Wireless Small Cells SIG event. The slide from his presentations neatly lays out the vision for shared spectrum.

In theory, even though this looks simple, in practice managing the database is a challenge by itself. The embedded slides below (Page 17 onwards) show the problems and the complexity associated with the database.
Time will tell how efficient and practical using whitespaces is.

Wednesday, 7 March 2012

Mobile Broadband: The Future Vision Document 2

Vision Paper incorporating comments and opinion from the online discusions on #MBBFuture

Available to download from slideshare here.

Sunday, 13 November 2011

2nd Workshop by 3GPP and Broadband Forum

3GPP and Broadband Forum held another joint session recently. Here is the summary from that event.
All presentations and documents from that event is available to download and view here.

Sunday, 16 October 2011

Broadband Adoption is Addictive

Click on the image to enlarge

From a presentation by Phillippe Keryer - Alcatel Lucent - BBWF 2011 Keynote Day 2

Saturday, 10 September 2011

Saturday, 30 July 2011

Wi-Fi in Public Transport over LTE

Another interesting presentation from the LTE World Summit 2011 on how LTE can be used as a backhaul in the trains to provide passenger WiFi and other services.

Wednesday, 2 March 2011

UMTS-LTE in 3.5GHz

There are two new bands: 3.4-3.6 GHz and 3.6-3.8 GHz decided for Broadband Wireless Access, which are already widely available for licensing in Europe. These bands have earlier been allocated to the Fixed Service on a primary basis in Region 1. Furthermore, the 3.4-3.6 GHz band was allocated to the mobile service on a primary basis and identified for IMT at WRC 07.

These bands constitute a substantial amount of spectrum that will be available in many countries in the short term. In Europe (Region 1) both bands can be used so block sizes could be large for any duplex arrangement.

The UMTS-LTE 3500 MHz Technical Report (3GPP TR 37.801) is already available as a study of current plans in the frequency bands 3.4-3.6 GHz and 3.6-3.8 GHz for UMTS and LTE systems. Specification work is due for first publication in March 2011 (TSG#51), with a series of specifications updated or being created.

The technical report is embedded below:

Thursday, 3 February 2011

4G Mobile Broadband Evolution: 3GPP Release-10 and Beyond

New Report from 4G Americas:

4G Mobile Broadband Evolution: 3GPP Release 10 and Beyond - HSPA+ SAE/LTE and LTE-Advanced provides detailed discussions of Release 10, including the significant new technology enhancements to LTE/EPC (called LTE-Advanced) that were determined in October 2010 to have successfully met all of the criteria established by the International Telecommunication Union Radiotelecommunication Sector (ITU-R) for the first release of IMT-Advanced. IMT-Advanced, which includes LTE-Advanced, provides a global platform on which to build next generations of interactive mobile services that will provide faster data access, enhanced roaming capabilities, unified messaging and broadband multimedia. The paper also provides detailed information on the introduction of LTE-Advanced and the planning for Release 11 and beyond. Release 10 is expected to be finalized in March 2011, while work on Release 11 will continue through the fourth quarter of 2012.

White paper embedded below and is available to view and download from the 3G4G website.

Tuesday, 4 January 2011

Mobile Broadband Enablers in future

From a presentation by Huawei at the New Zealand Future Wireless Technologies Seminar. The presentation is available here.

Monday, 18 October 2010

TETRA Evolution

Couple of Interesting presentation on TETRA Evolution.

Thursday, 16 September 2010

Against the Limited "Unlimited" data plans

Once upon a time the Mobile Operators had loads of bandwidth and not enough data users. So they decided to lure the poor users into buying the 'unlimited' data plans. They were sure that the devices are quite rubbish and no one can use enough data. Just for the precaution some clever operators added a small print where unlimited meant 1 or 2GB. The operators thought that the users will never reach this amount.

Then came the iPhone and changed the whole world. People actually started using the data on their devices. The operators started panicking. Android just compunded this problem. So the operators now have started advocating against these unlimited plans.

The CEO of Vodafone , Vittorio Colao , has told attendees at this year's Nokia World 2010 event that he welcomes the end of "unlimited" Mobile Broadband data plans. Colao also warned consumers that "data pricing has to adjust", thus signalling a greater focus on tiered pricing models.

He added: "The principle here must be that, a bit like motorways or hotels, every class of service needs to have its own price and customers must be able to pay for the level of service [they want]. Pricing should be adjusted to reflect the usage and load. We are approaching the end of the free era."

The cowboy salesmen are still fooling the average Joe when it comes to unlimited plans. People sue the operators but dont succeed.

We are begging to see the return of those bad old days when WiFi was the only option in conferences, etc and they were really expensive. Now instead of WiFi we have got our dongles that may not work well anyway inside the conferences or hotels due to the structure or location but when they do, you again have to think about the costs.

In Korea, KT Telecom had to introduce unlimited plans because the other rival introduced one. This is probably because they still have spare bandwith available. Once that gets used up then they will either be running for caps or advocating against the unlimited plans.

I have been against the unlimited plans from the beginning but I advocate that the operators become a bit wise in the way they charge us, the end users.

If I have 4 devices I dont want limited data on all devices because I dont want to keep track of which devices use how much data or have an allowance. Maybe what I need is a data bundle that I can use across devices and maybe share with my family members. Wallmart has recently come up with something similar in US. Wallmart is a MVNO using T-Mobile network. Though their data plans are expensive compared to T-Mobiles plans just because they allow data sharing and rollover, people may go for them.

Rollovers are available on Pay as you go plans but not on Pay monthly which makes the pay monthly (generally on contract) people seem stupid. Operators should encourage this, maybe keep a maximum that can be rolled over.

Finally, there is this net neutrality and QoS discussions are going on. Eventually some kind of QoS or destination based speeds, etc will come but for the end user they will go where they will get what they want. The operators should remember this.