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Showing posts with label Spectrum. Show all posts
Showing posts with label Spectrum. Show all posts

Monday, 3 February 2014

5G and the ‘Millimeter-Wave' Radios


There were quite a few interesting talks in the Cambridge Wireless Radio Technology SIG event last week. The ones that caught my attention and I want to highlight here are as follows.

The mobile operator EE and 5GIC centre explained the challenges faced during the Practical deployments. Of particular interest was the considerations during deployments. The outdoor environments can change in no time with things like foliage, signage or even during certain festivals. This can impact the radio path and may knock out certain small cells or backhaul. The presentation is available to view and download here.


Another interesting presentation was from Bluwireless on the 60GHz for backhaul. The slide that was really shocking was the impact of regulation in the US and the EU. This regulation difference means that a backhaul link could be expensive and impractical in certain scenarios in the EU while similar deployments in the US would be considerably cheaper. This presentation is available here.


Finally, the presentation from Samsung highlighted their vision and showed the test results of their mmWave prototype. The presentation is embedded below and is available here.



Finally, our 5G presentation summarising our opinion and what 5G may contain is available here. Dont forget to see the interesting discussion in the comments area.

Monday, 3 June 2013

New Carrier Type (NCT) in Release-12 and Band 29

One of the changes being worked on and is already available in Release-11 is the Band 29. Band 29 is a special FDD band which only has a downlink component and no uplink component. The intention is that this band is available an an SCell (Secondary cell) in CA (Carrier Aggregation). 

What this means is that if this is only available as an SCell, any UE that is pre-Rel-11 should not try to use this band. It should not read the system information, reference information, etc. In fact the System Information serves little or no purpose as in CA, the PCell will provide the necessary information for this SCell when adding it using the RRC Reconfiguration message. This gives rise to what 3GPP terms as New Carrier Type for LTE as defined here. An IEEE paper published not long back is embedded below that also describes this feature in detail. 

The main thing to note from the IEEE paper is what they have shown as the unnecessary information being removed to make the carrier lean.

China Mobile, in their Rel-12 workshop presentation, have suggested 3 different types/possibilities for the NCT for what they call as LTE-Hi (Hi = Hotspot and Indoor).

Ericsson, in their Rel-12 whitepaper mention the following with regards to NCT:

Network energy efficiency is to a large extent an implementation issue. However, specific features of the LTE technical specifications may improve energy efficiency. This is especially true for higher-power macro sites, where a substantial part of the energy consumption of the cell site is directly or indirectly caused by the power amplifier.

The energy consumption of the power amplifiers currently available is far from proportional to the power-amplifier output power. On the contrary, the power amplifier consumes a non-negligible amount of energy even at low output power, for example when only limited control signaling is being transmitted within an “empty” cell.

Minimizing the transmission activity of such “always-on” signals is essential, as it allows base stations to turn off transmission circuitry when there is no data to transmit. Eliminating unnecessary transmissions also reduces interference, leading to improved data rates at low to medium load in both homogeneous as well as heterogeneous deployments.

A new carrier type is considered for Release 12 to address these issues. Part of the design has already taken place within 3GPP, with transmission of cell-specific reference signals being removed in four out of five sub frames. Network energy consumption can be further improved by enhancements to idle-mode support.

The IEEE paper I mentioned above is as follows:



Saturday, 23 March 2013

LTE for Public Safety Networks

The last presentation on this topic couple of months back has reached nearly 7K views so here is another one from a recent article on the same topic from IEEE Communications Magazine



Thursday, 14 February 2013

Scalable UMTS (S-UMTS) to accelerate GSM Refarming


Looks like a good idea from LTE will possibly be applied to UMTS/HSPA and it will also help accelerate the re-farming of GSM spectrum. A recent presentation from Qualcomm below:



Available to download from here.

Saturday, 15 December 2012

Spectrum auction results from The Netherlands



The result of the auction: 

8009001800210019002600
KPN2x102x102x202x5
 30
Vodafone2x102x102x202x5

T-Mobile
2x152x30
4,9+9,7 25
 Tele22x10




The total price of the auction:
  • Vodafone 1,380,800,000 euro (1.381 billion)
  • KPN 1,351,852,000 euros (1.352 billion)
  • T-Mobile 910,681,000 euro (910.8 million)
  • Tele2 euro 160,813,000 (160.8 million)
After the auction is the distribution of the main bands is as follows:
 800900 no  900 new 1800 no 1800 new 2100 no 2100 new 2600
 KPN2x10  2x12,4 2x10 2x18,4 2x20 2x15 2x20 2x10
 Vodafone2x10 2x12,4 2x10 2x4,8 2x20 2x15 2x20 2x10
 T-Mobile 2x10 2x15 2x30,6 2x30 2x20 2x20 2x5
 Tele22x10 - - - - - - 2x20
 TO - - - - - 2x20

Sources:

LTE Rollouts planned:
Vodafone - Summer 2013
KPN - February 2013

Added 15/12/12:11.48

You can also see it visually as in the slide below:




Wednesday, 12 September 2012

UK: Spectrum, Operators, Vendors and LTE

So LTE (or '4G') is about to be launched in the UK as announced yesterday. Its going to be branded as 4GEE.

Here is a summary of the Spectrum in the UK that will be used for LTE and would be auctioned by Ofcom.


Here is the current allocation of Spectrum in the UK

The above pics are from a presentation by Ofcom in LTE World Summit 2012 in Barcelona, available here.



The last table is from an Ofcom document here. Its very interesting read. For example I didnt know that The L-band was the first major part of Ofcom spectrum awards programme relevant to mobile services. It consists of 40MHz between 1452MHz and 1492MHz. The auction took place in May 2008, in which Qualcomm won the entirety of the available spectrum.

Here is the summary of the operators working on LTE:


Everything Everywhere (EE = Orange + T-Mobile) - They are calling their '4G' service as EE, covering up to 70% of the UK by the end of 2013. Network kit provided by Huawei.

Three - Samsung will provide the Radio Access Network, and the core infrastructure, for Three's LTE (4G) network. That includes the base stations, and radio core. 3 UK has agreed to purchase 2 x 15 MHz of 1800 MHz spectrum from Everything everywhere, and plans commercial launch of LTE service in 2013.

Telefonica (O2) trial network - Equipment supplied by Nokia Siemens Networks (NSN) for both the Radio and Core network elements. Backhaul for the 4G trial network has been provided using Microwave Radio Equipment from Cambridge Broadband Networks Limited, NEC and Nokia Siemens Networks.

Updated 13/09/12 - 11:25

UK Broadband rolled out the first commercial TD-LTE network in London back in February (available to customers since May 2012). The equipment is provided by Huawei. They have 40MHz in Band 42 (3.5GHz) and 84MHz in band 43 (3.6GHz).

Vodafone - No news.


Anything else I missed?

Tuesday, 11 September 2012

New Carrier-Aggregation Proposed Bands

Carrier Aggregation (CA) the promised feature of LTE-A that will make it compatible to IMT-A is not fully exploited in Rel-10. There are only 2 bands supported for CA in Rel-10 and the same for Rel-11. The following are the bands for Rel-10

And the following for Rel-11

Unfortunately these are not enough for all the operators launching LTE/LTE-A. As a result there is currently a study on lots of other bands ongoing within 3GPP. Here is my understanding of the bands that would be needed and the region where they would be needed. Interested in knowing if there are other operators/regions where other bands need to be included.
 

Wednesday, 5 September 2012

Qualcomm's 1000x Challenge

Qualcomm has been promoting the '1000x' challenge and has recently held a webinar to make everyone aware of how 1000 times efficiency may be achieved. I think there is always a scope of achieving a better efficiency but putting a figure may not necessarily give the desired results. Anyway, here are the slides.



You can listen to the webinar here. The promotional video is available here.

A writeup on this topic by Steven Crowley 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.







Thursday, 12 April 2012

Whitespaces Standards


Continuing on the same topic of whitespaces from yesterday, we try and see who is working on the standardisation of whitespaces

IETF Protocol to Access White Space database (PAWS)

The charter for this WG was established 14 June 2011. Generally, the IETF strives to utilise established protocols rather than develop new ones. The objecives of this WG are:
  • Standardise a mechanism for discovering a white space database
  • Standardise a mechanism for accessing a white space database
  • Standardise query and response formats to be carried over the database access method
  • Ensure that the discovery mechanism, database access method and query response formats have appropriate security levels in place.
The WG goals are:
  • April 2012 Submit ‘Use-cases and Requirements for Accessing a Radio White Space Database’ to the IESG for publication as Informational. The current draft of this document is here: http://datatracker.ietf.org/doc/draft-ietf-paws-problem-stmt-usecases-rqmts/
  • December 2012, Submit ‘Accessing a Radio White Space Database’ to the IESG for publication as a Proposed Standard.

ETSI Reconfigurable Radio Systems (RRS)


The ETSI Technical Committee (TC) on Reconfigurable Radio Systems (RRS) has the responsibility for standardization activities related to Reconfigurable Radio Systems encompassing system solutions related to Software Defined Radio (SDR) and Cognitive Radio (CR), to collect and define the related Reconfigurable Radio Systems requirements from relevant stakeholders and to identify gaps, where existing ETSI standards do not fulfil the requirements, and suggest further standardization activities to fill those gaps.

IEEE Dynamic Spectrum Access Networks Standards Committee (DySPAN-SC)


The scope of the IEEE Dynamic Spectrum Access Networks Standards Committee (DySPAN-SC), which was formerly IEEE SCC41 until 2010, includes the following [1]:
  • dynamic spectrum access radio systems and networks with the focus on improved use of spectrum,
  • new techniques and methods of dynamic spectrum access including the management of radio transmission interference, and
  • coordination of wireless technologies including network management and information sharing amongst networks deploying different wireless technologies.
In December 2010 the IEEE SCC41 was re-organized as IEEE DySPAN-SC and its sponsor was changed from the IEEE Standards Coordinating Committee (SCC) to the IEEE Communications Society Standards Development Board (CSDB).
Included in the IEEE DySPAN SC are following working groups[1]:
  • 1900.1 Working Group on Definitions and Concepts for Dynamic Spectrum Access: Terminology Relating to Emerging Wireless Networks, System Functionality, and Spectrum Management
  • 1900.2 Working Group on Recommended Practice for Interference and Coexistence Analysis of In-Band and Adjacent Band Interference and Coexistence Between Radio Systems
  • 1900.4 Working Group on Architectural Building Blocks Enabling Network-Device Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless Access Networks
  • 1900.5 Working Group on Policy Language and Policy Architectures for Managing Cognitive Radio for Dynamic Spectrum Access Applications
  • 1900.6 Working Group on Spectrum Sensing Interfaces and Data Structures for Dynamic Spectrum Access and other Advanced Radio Communication Systems
  •  P1900.7 White Space Radio Working Group: Radio Interface for White Space Dynamic Spectrum Access Radio Systems Supporting Fixed and Mobile Operation
  • Ad hoc group on Dynamic Spectrum Access in Vehicular Environments (DSA-VE)
DySPAN SC is currently one of the most active standardization bodies for dynamic spectrum access radio systems and networks. 


CEPT/ECC WG Spectrum Engineering (SE), project team SE43

The ECC WGSE (Spectrum Engineering) has set up a special project dealing with cognitive radio matters. The SE43 was set up in May 2009 and finished its work in January 2011 by completing the ECC Report “Technical and Operational Requirements for the Possible Operation of Cognitive Radio Systems in the ‘White Spaces’ of the Frequency Band 470-790 MHz”The WG SE adopted the ECC Report 159 on white space devices for publication, in January 2011. This report can be downloaded from the undefinedCEPT/ECC website.

The main focus of the report is, as the title suggest, on coexistence with incumbent or primary systems. It contains definitions of “White Space”, cognitive radio and introduces the term “White Space Device” – WSD. The latter being the term used for the cognitive radio unit. The definition of “White Space” is taken from CEPT Report 24 “Technical considerations regarding harmonisation options for the Digital Dividend “ The report defines different scenarios for CR operation in terms of WSD types (personal/portable, home/office and public access points) and also discusses the three well known types of cognitive techniques: spectrum sensing, geo-location and beacons.
The report is focussed on protection of four possible incumbent systems: broadcast systems (BS), Program making and special events (PMSE), radio astronomy (RAS) and aeronautical radio navigation systems (ARNS). Comprehensive data on possible sensing and separation distances are given, and ends in operational and technical characteristics for white spaces devices to operate in the band. An estimate of available white space is also included.


Wightless


Weightless operates in an 8MHz-wide channel, to fit into the slots used for broadcast TV (and will thus have to squeeze into 6MHz if used across the pond where TV is smaller). Weightless is a Time Division Duplex (TDD) protocol, so access point and clients take turns to transmit.

When the hub device checks with the national database, it supplies a location and receives a list of 8MHz slots which aren't being used to transmit TV in that location. Weightless will hop between available slots every second or so, skipping any which turn out to be too cluttered (though periodically checking back in case they've cleared).

Showing its M2M roots, a Weightless access point only pages connected devices every 15 minutes, so those devices only need power up the radio four times an hour. Neul reckons that running the radio for two seconds at such intervals results in power consumption roughly equal to the decay rate of an idle battery, so being connected (and idle) has no perceivable impact on battery life.

That means a single Weightless hub can run connections to hundreds devices, across a network spanning 10km or so. Those devices could easily have a battery life measured in years, and be capable of responding with megabytes of data within 15 minutes.

A device which wants to connect to the network won't want to wait that long, and neither will one with something to report. In such circumstances the client can pick up a transmitted frame, which comes every second or two, and register an interest in sending some data upstream.

The security side of Weightless has yet to be worked out, with mutual authentication being considered more important than encrypting the content. Having someone listening in to a meter reading isn't that important, having someone faking a reading is, and content can always be encrypted at a higher level (Weightless will happily carry IPv4 and IPv6 packets).

Once on the network, a device has to wait for the hub to say when it can talk, though it has the chance to request communication slots. The speed of transmission is dependent on the quality of the signal. Each frame is addressed in a basically encoded header; all other devices can switch off their radios once they know the frame isn't addressed to them, and if the receiving device is nearby (as established by the signal strength) then the rest of the frame can be tightly encoded in the knowledge that little will be lost en route.

That means a Weightless hub can speak to hundreds of devices on the same network, with the speed of connection varying between devices. A receiver near the hub might therefore get 10Mb/sec or better, but one operating on the same network, from the same hub, could be running at a few hundred Kb in the same timeframe.


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, 28 March 2012

Platinum Band: Sub 1GHz Frequency Band


Was listening to the Softbank webcast earlier about why they are so happy on receiving the 900MHz spectrum. The extract from slidepack summarises the advantages on this 'Platinum Band'

Monday, 12 March 2012

Problems with 800MHz in UK and Spectrum to be auctioned


Even though 800MHz provides far better coverage than 2.1GHz (as shown above), it is going to be difficult to rollout LTE on 800MHz in the short term. The main reason being that there are quite a few other devices that use the frequencies or the frequencies neighbouring the 800MHz band and the interference may stop them working. A chart of the users is shown below.


It would be interesting to see when the rollouts in 800MHz would happen.

According to Ofcom, the following spectrum will be available in the UK:


• 250MHz of spectrum:
    • 2x30MHz paired at 800MHz
    • 2x70MHz paired at 2.6GHz
    • 50MHz unpaired at 2.6GHz
• (Also 2x15MHz of 1800MHz spectrum to be divested by EE)
• Starts to become available from Jan 2013
    • 800MHz expected to be available across whole of the UK by end of 2013
    • 2.6GHz across majority of UK by end of 2013 with remaining areas asap thereafter



All these topics were recently covered in a Cambridge Wireless event on Mobile Broadband SIG: Mobile Broadband in Rural Areas. The presentations are available here to view and download.