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

Friday 4 January 2013

Energy-efficient femtocell implementation

In an earlier post, we saw an idea on how to have energy efficient Femtocell. Here is a practical implementation from ALU on energy efficient Femtocell.



Thursday 27 December 2012

Small Cells 'Terminology' and 'Comparison'


Here is AT&T's attempt in comparing the small cells. The above comparison is probably based on the assumption that LTE Small cells are not yet widely available. Once they are, then LTE can be put in for most columns in the Technology part.

See also:



Thursday 29 November 2012

Hotspot 2.0, Next Generation Hotspot (NGH), etc.


From ZDNET:


Hotspot 2.0 is about certifying the hotspot itself, providing authentication using SIMs or certificates and the 802.11i standard, and using the recent 802.11u standard to provide performance and other information about the hotspots visible to a device. This will allow you to roam onto a hotspot with good connectivity that you have the right account to use, doing away with the need to select the network or enter your details into a web page, as you do today.

The Wi-Fi Alliance deals with the Wi-Fi hardware and the authentication specification under the name Passpoint, but this certification doesn't cover everything. The Wireless Broadband Alliance is a group of mobile and Wi-Fi operators that takes the Passpoint certification and ensures interoperability with other parts of the network — including authenticating to carriers' remote access RADIUS (Remote Authentication Dial-In User Service) servers, as well as roaming and billing.

"Next Generation Hotspot is the implementation of Hotspot 2.0 into a real, live network", explains Nigel Bird, the NGH Standardisation Manager at Orange Group.

From Next Generation Hotspot whitepaper:


A new program called Next Generation Hotspot (NGH) - using the latest HotSpot 2.0 specification1 - allows a mobile subscriber to connect automatically and securely to Hotspots using his service provider credentials while maintaining roaming visibility for the operator. NGH enables operators to continuously monitor and manage “cellular-like” service over Wi-Fi domestically and internationally so as to enhance performance and meet the demand for mobile data services over heterogeneous RANs - cellular and Wi-Fi. This enables mobile operators to simultaneously optimize backhaul throughput, offload specific traffic rapidly (e.g. video) and achieve better economics than traditional, cellular-only solutions.

The Wireless Broadband Appliance (WBA) and Small Cells Forum recently announced collaboration on this topic, see here.

More details are available in this presentation embedded below:



Monday 3 September 2012

Cellular or WiFi: Which is the preferred network access?

I was going through this report by Cisco on "What do Consumers want from WiFi" and came across this interesting picture. 

With the ease and availability of easy WiFi, it would be the preferred access technology whenever possible. Cellular access would be generally reserved for mobility scenarios or where there is no wifi network to allow access.

Another interesting observation from above is that the survey puts WiFi and Cellular security to the same level. Though the cellular is more secure in case of an open public WiFi scenario where an eavesdropper may be able to get hold of login/password information it is generally at the same level of security to a secured WiFi. On the other hand with cellular, lawful interception may be much more easy as compared to using secure WiFi.

I am sure that the content of last paragraph are debatable and am happy to hear your viewpoints.

A slidecast of the Cisco whitepaper mentioned above is embedded as follows:



Thursday 19 July 2012

Seamless offloading between Cellular Network and WLAN (CNW)

Last month I wrote a post about the 'Virtual Femtocell' concept. Apparently there is a company already doing this. The following is from GigaOm:



SR-Mobile, a Korean company that also has offices in Plano, Texas, is looking to help cellular carriers make seamless handoffs with Wi-Fi networks, enabling them to easily offload traffic from their cellular networks. The company, which is demonstrating its technology later this month at the Mobile Asia Expo, allows a carrier to switch a call or data traffic seamlessly between Wi-Fi, 3G and 4G. It does this with the help of a virtual radio agent mobile application on a mobile device that automatically switches between cellular and Wi-Fi modems. The VRA app works with a smart radio mobile controller that can access the network server and transfers the network traffic to the network core.


The benefit of this approach is that it allows a Wi-Fi hotspot to act as a virtual base station, which can be easily added and managed by an operator. If there’s capacity on the Wi-Fi network, it can seamlessly handle calls and data but if it gets overcrowded, it can switch back to the cellular network. SR’s approach also means that a carrier can expand their network capacity without a lot of investment, by relying on their existing Wi-Fi network or their user’s private Wi-Fi network. SR, which was founded by James Lee, a former senior staffer at Samsung Telecom America, is working on a trial with Korean operator KT, which will test SR’s technology on select LG phones.

More details about their solution in their presentation below:



Wednesday 18 July 2012

Real Life Pictures of Small Cells Deployments in London

Visitors of this blog seemed to like the last set of deployment pictures I put up. As a result here is another set of pictures from the same Telefonica presentation by Robert Joyce. See also my earlier post on the same topic here.













Friday 15 June 2012

Three Phases of WiFi Integration


From a presentation by Ericsson in the LTE World Summit 2012. Presentation available here.

Operator WiFi is becoming an important proposition and there are advantages and disadvantages of both of them. The above picture summarises the phases in which it may take place.

See also:

Monday 11 June 2012

The 'Virtual' Femtocell and a competition for OTT Apps

Over the last few months we have been thinking of so many ideas around small cells and this is something that we thought. It looks very simple and straightforward and having talked to a few small cells experts, off the record, none of them seem to be able to see anything wrong with this concept. With the 'Small Cells World Summit' just round the corner I am sure this could be something worth a discussion.

I am explaining the concept using an HSPA+ setup but there is no reason why this would not work in an LTE Setup. This is a typical connection for HSPA+ Femtocell setup with the gateway acting as a concentrator for all Iuh connections and having a single Iu connection towards the core. I have not shown CS/PS connection separately for simplicity. 
We propose a 'Virtual' or 'Invisible' Femtocell concept where we think that the Femtocell is redundant but the concept can be used to avoid the coverage and capacity problems faced by the operators and at the same time avoid the 'Signalling storm', atleast on the access network side. Now most smartphones have WiFi stack inbuilt. For this concept to work, WiFi in the phone is a must. Instead of having a Femtocell in between, a modified stack could be embedded in the phone itself. The output of the phone over WiFi are the Iuh messages that can terminate at the gateway and no difference would be needed from the core network side. This is illustrated in the picture below.
The phones would also need to have an enhanced UI to be able to allow a user to select only this option when roaming. You don't want a situation where the user thinks that he is camped on the 'Virtual' femtocell and making/receiving calls while he is not and run up a huge bill.

Advantages of this approach:

  • The Femtocells are no longer really needed and the end customer does not require to buy a separate equipment, which is different for different operators.
  • The phones can be working whenever a reliable WiFi connection is available, even if they are abroad without incurring costly roaming charges.
  • Some operators that do not have a lot of spectrum available avoid using Femtocells as they can cause interference and black holes in the coverage. 
  • There is no worry of a femtocell being used abroad illegally thereby causing interference with spectrum in another country.
  • Some security issues can be totally avoided and it would be worth for the operators that the keys being used cannot be seen by others.
  • A lot of people use OTT apps like Skype, Viber, Whatsapp when abroad, being camped on WiFi to avoid costly roaming charges. This approach would mean that the normal Voice and Messaging becomes similar to OTT and can help operator avoid losing out to the OTT apps. 


Disadvantages of this approach:

  • WiFi spectrum is already congested and does not always give reliable coverage.
  • Security issues would have to be looked in detail to make sure this would be secure enough. Since this concept is similar to creating a VPN between the phone and the gateway, I wouldnt think there would be any issues though.
  • Roaming revenues are a big cash cow for the operators, most of them would be unwilling to lose this if the phones are using this approach.

I think this concept is more suitable for the Residential Femtocells rather than the other Small Cells (enterprise, metro, pico, etc.) and there will always be a need for them. The main reason being that on a large scale, WiFi is extremely unreliable, prone to interference and not future proofed. A new device may cause interference that may take forever to resolve. Operating a small cell in the licensed spectrum would always make sense and the reliability would be much higher.

If you think this makes sense please click the 'Useful' checkbox so that I know.

As a company we are always looking to engage with other companies to discuss similar ideas. If you are a company dealing with Small Cells and are open to discussing similar ideas, please let us know.

Wednesday 6 June 2012

Integration of Wi-Fi with Cellular Networks

Presented by Tiago Rodrigues in the ITM Optimisation event in Prague on 18th April 2012.

There is another paper by NSN on the same topic that is available here

Tuesday 8 May 2012

WiFi: Standards, Spectrum and Deployment

Yesterday, IEEE published its fourth revision to 802.11. The updates include faster throughput, improved cellular hand-offs, and better communication between vehicles in addition to other improvements.The following from IEEE website:

The new IEEE 802.11-2012 revision1 has been expanded significantly by supporting devices and networks that are faster, more secure, while offering improved Quality of Service and, improved cellular network hand-off. IEEE 802.11 standards, often referred to as “Wi-Fi®,” already underpin wireless networking applications around the world, such as wireless access to the Internet from offices, homes, airports, hotels, restaurants, trains and aircraft around the world. The standard’s relevance continues to expand with the emergence of new applications, such as the smart grid, which augments the facility for electricity generation, distribution, delivery and consumption with a two-way, end-to-end network for communications and control.

IEEE 802.11 defines one MAC and several PHY specifications for wireless connectivity for fixed, portable and mobile stations. IEEE 802.11-2012 is the fourth revision of the standard to be released since its initial publication in 1997. In addition to incorporating various technical updates and enhancements, IEEE 802.11-2012 consolidates 10 amendments to the base standard that were approved since IEEE 802.11’s last full revision, in 2007. IEEE 802.11n™, for example, defined MAC and PHY modifications to enable much higher throughputs, with a maximum of 600Mb/s; other amendments that have been incorporated into IEEE 802.11-2012 addressed direct-link setup, “fast roam,” radio resource measurement, operation in the 3650-3700MHz band, vehicular environments, mesh networking, security, broadcast/multicast and unicast data delivery, interworking with external networks and network management.

“The new IEEE 802.11 release is the product of an evolutionary process that has played out over five years and drawn on the expertise and efforts of hundreds of participants worldwide. More than 300 voters from a sweeping cross-section of global industry contributed to the new standard, which has roughly doubled in size since its last published revision,” said Bruce Kraemer, chair of the IEEE 802.11 working group. “Every day, about two million products that contain IEEE 802.11-based technology for wireless communications are shipped around the world. Continuous enhancement of the standard has helped drive technical innovation and global market growth. And work on the next generation of IEEE 802.11 already has commenced with a variety of project goals including extensions that will increase the data rate by a factor of 10, improve audio/video delivery, increase range and decrease power consumption.”

1 IEEE 802.11™-2012 “Standard for Information technology--Telecommunications and information exchange between systems Local and metropolitan area networks--Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”


The following is from a presentation by Agilent in LTE World Summit last year. It summarises the 802.11 standards, the Spectrum available and deployment use cases.







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 23 November 2011

Secure Wi-Fi for Large Scale Events and Arenas

Interesting presentation from Logica on Secure WiFi. The resolution of this presentation is low for security reasons as well, I guess.
To download this presentation and other presentation from the recent event, click here.