Showing posts with label Public Safety Comm. Show all posts
Showing posts with label Public Safety Comm. Show all posts

Tuesday, 5 December 2017

Summary of 3GPP Release-14 Work Items


With all focus on 5G (Release-15), looks like Rel-14 has been feeling a bit neglected. There are some important updates though as it lays foundation for other services.

3GPP used to maintain Release Descriptions here for all different releases but have stopped doing that since 2014. For Release-14, a new document "3GPP TR 21.914: Release 14 Description; Summary of Rel-14 Work Items" is now available here.

An executive summary from the document:

Release 14 focusses on the following items:
  • Improving the Mission Critical aspects, in particular with the introduction of Video and Data services
  • Introducing the Vehicle-to-Everything (V2X) aspects, in particular the Vehicle-to-Vehicle (V2)
  • Improving the Cellular Internet of Things (CIoT) aspects, with 2G, 3G and 4G support of Machine-Type of Communications (MTC)
  • Improving the radio interface, in particular by enhancing the aspects related to coordination with WLAN and unlicensed spectrum
  • A set of uncorrelated improvements, e.g. on Voice over LTE (VoLTE), IMS, Location reporting.


The continuation of this document provides an exhaustive view of all the items specified by 3GPP in Release 14.

I have blogged about the Mission Critical Communications here. 3GPP has also done a webinar on this topic which can be viewed here. I like this slide below that summarizes features in different releases.

Then there are quite a few new features and enhancements for V2X. I have blogged about sidelink and its proposed extensions here.

From the document:

The Work Item on “Architecture enhancements for LTE support of V2X services (V2XARC)”, driven by SA WG2, specifies the V2X architectures, functional entities involved for V2X communication, interfaces, provisioned parameters and procedures in TS 23.285.
Figure above depicts an overall architecture for V2X communication. V2X Control Function is the logical function defined for network related actions required for V2X and performs authorization and provisioning of necessary parameters for V2X communication to the UE via V3 interface.

A UE can send V2X messages over PC5 interface by using network scheduled operation mode (i.e. centralized scheduling) and UE autonomous resources selection mode (i.e. distributed scheduling) when the UE is "served by E-UTRAN" while a UE can send V2X messages over PC5 interface only by using UE autonomous resources selection mode when the UE is "not served by E-UTRAN". 

Both IP based and non-IP based V2X messages over PC5 are supported. For IP based V2X messages over PC5, only IPv6 is used. PPPP (ProSe Per-Packet Priority) reflecting priority and latency for V2X message is applied to schedule the transmission of V2X message over PC5.

A UE can send V2X messages over LTE-Uu interface destined to a locally relevant V2X Application Server, and the V2X Application Server delivers the V2X messages to the UE(s) in a target area using unicast delivery and/or MBMS (Multimedia Broadcast/Multicast Service) delivery.

Both IP based and non-IP based V2X messages are supported for V2X communication over LTE-Uu. In order to transmit non-IP based V2X messages over LTE-Uu, the UE encapsulates the V2X messages in IP packets.

For latency improvements for MBMS, localized MBMS can be considered for localized routing of V2X messages destined to UEs.

For V2X communication over LTE-Uu interface, the V2X messages can be delivered via Non-GBR bearer (i.e. an IP transmission path with no reserved bitrate resources) as well as GBR bearer (i.e. an IP transmission path with reserved (guaranteed) bitrate resources). In order to meet the latency requirement for V2X message delivery, the following standardized QCI (QoS Class Identifier) values defined in TS 23.203 can be used:
  • QCI 3 (GBR bearer) and QCI 79 (Non-GBR bearer) can be used for the unicast delivery of V2X messages.
  • QCI 75 (GBR bearer) is only used for the delivery of V2X messages over MBMS bearers. 


There are updates to cellular IoT (CIot) which I have blogged about here.

There are some other interesting topic that are enhanced as part of Release14. Here are some of them:
  • S8 Home Routing Architecture for VoLTE
    • Robust Call Setup for VoLTE subscriber in LTE
    • Enhancements to Domain Selection between VoLTE and CDMA CS
    • MBMS improvements
    • eMBMS enhancements for LTE
    • IMS related items
    • Evolution to and Interworking with eCall in IMS
    • Password-based service activation for IMS Multimedia Telephony service
    • Multimedia Priority Service Modifications
    • Enhancements to Multi-stream Multiparty Conferencing Media Handling
    • Enhancement for TV service
    • Improved Streaming QoE Reporting in 3GPP (IQoE)
    • Quality of Experience (QoE) Measurement Collection for streaming services in UTRAN
    • Development of super-wideband and fullband P.835
    • Enhancements to User Location Reporting Support
    • Enhancing Location Capabilities for Indoor and Outdoor Emergency Communications
    • Further Indoor Positioning Enhancements for UTRA and LTE
    • Improvements of awareness of user location change
    • Terminating Access Domain Selection (T-ADS) supporting WLAN Access
    • Enhanced LTE-WLAN Aggregation (LWA)
    • Enhanced LTE WLAN Radio Level Integration with IPsec Tunnel (eLWIP)
    • Positioning Enhancements for GERAN
    • New GPRS algorithms for EASE
    • RRC optimization for UMTS
    • Multi-Carrier Enhancements for UMTS
    • DTX/DRX enhancements in CELL_FACH
    • LTE radio improvements
    • Enhancements on Full-Dimension (FD) MIMO for LTE
    • Downlink Multiuser Superposition Transmission for LTE
    • Performance enhancements for high speed scenario in LTE
    • Control and User Plane Separation (CUPS) of EPC nodes
    • Paging Policy Enhancements and Procedure
    • Shared Subscription Data Update
    • Service Domain Centralization
    • Control of Applications when Third party Servers encounter difficulties
    • PS Data Off Services
    • Enhancement to Flexible Mobile Service Steering 
    • Sponsored data connectivity improvements
    • Group based enhancements in the network capability exposure functions
    • Improved operator control using new UE configuration parameters
    • Charging and OAM stand alone improvements
    • Rel-14 Charging
    • ...

    Further Reading:


    Tuesday, 27 June 2017

    Mission Critical Services update from 3GPP - June 2017


    3GPP has published an overview of what has been achieved so far in the Mission Critical and also provides an outlook of what can be expected in the near future. A more detailed paper summarizing the use cases and functional aspects of Rel-13, Rel-14 and upcoming Rel-15 will be published later this year.

    Mission Critical Services – Detailed List of Rel-13, Rel-14 and Rel-15 Functionalities

    Rel-13 MCPTT (completed 2016)
    • User authentication and service authorization
    • Configuration
    • Affiliation and de-affiliation
    • Group calls on-network and off-network (within one system or multiple systems, pre-arranged or chat model, late entry, broadcast group calls, emergency group calls, imminent peril group calls, emergency alerts)
    • Private calls on-network and off-network (automatic or manual commencement modes, emergency private calls)
    • MCPTT security
    • Encryption (media and control signalling)
    • Simultaneous sessions for call
    • Dynamic group management (group regrouping)
    • Floor control in on-network (within one system or across systems) and in off-network
    • Pre-established sessions
    • Resource management (unicast, multicast, modification, shared priority)
    • Multicast/Unicast bearer control, MBMS (Multimedia Broadcast/Multicast Service) bearers
    • Location configuration, reporting and triggering
    • Use of UE-to-network relays
    Rel-14 MC Services (completed 2017)
    MC Services Common Functionalities:
    • User authentication and service authorization
    • Service configuration
    • Affiliation and de-affiliation
    • Extended Location Features
    • (Dynamic) Group Management
    • Identity management
    • MC Security framework
    • Encryption (media and control signalling)
    MCPTT Enhancements:
    • First-to-answer call setup (with and without floor control)
    • Floor control for audio cut-in enabled group
    • Updating the selected MC Service user profile for an MC Service
    • Ambient listening call
    • MCPTT private call-back request
    • Remote change of selected group
    MCVideo, Common Functions plus:
    • Group Call (including emergency group calls, imminent peril group calls, emergency alerts)
    • Private Call (off-network)
    • Transmission Control
    MCData, Common Functions plus:
    • Short Data Service (SDS)
    • File Distribution (FD) (on-network)
    • Transmission and Reception Control
    • Handling of Disposition Notifications
    • Communication Release
    Rel-15 MC Services (in progress)

    MC Services Common Functionalities Enhancements:
    • Enhanced MCPTT group call setup procedure with MBMS bearer
    • Enhanced Location management, information and triggers
    • Interconnection between 3GPP defined MC systems
    • Interworking with legacy systems

    MCPTT Enhancements:
    • Remotely initiated MCPTT call
    • Enhanced handling of MCPTT Emergency Alerts
    • Enhanced Broadcast group call
    • Updating pre-selected MC Service user profile
    • Temporary group call - user regroup
    • Functional alias identity for user and equipment
    • Multiple simultaneous users
    MCVideo Additions:
    • Video push
    • Video pull
    • Private call (on-network)
    • Broadcast Group Call
    • Ambient Viewing Call
    • Capability information sharing
    • Simultaneous Sessions
    • Use of MBMS transmission
    • Emergency and imminent peril private communications
    • Primary and Partner MC system interactions for MCVideo communications
    • Remote video parameters control capabilities

    MCData Additions:
    • MCData specific Location
    • Enhanced Status
    • Accessing list of deferred communications
    • Usage of MBMS
    • Emergency Alert
    • Data streaming
    • File Distribution (FD) (off-network)
    • IP connectivity

    Release-14 features will be available by end of September 2017 and many Release-15 features, that is being hurried due to 5G will be available by June 2018.

    For more details, follow the links below:



    Sunday, 12 March 2017

    High Power / Performance User Equipment (#HPUE)

    3GPP refers to HPUE as High Power UE while the US operator Sprint prefers to use the term High Performance UE.

    HPUE was initially defined for US Public Safety Band 14 (700MHz). The intention was that this high power UEs can increase the coverage range from 4km to 8km. This would mean larger coverage areas and less number of cells.

    While the commercial UE's (class 3) transmit at +23dBm (max 200mW), the Public Safety people intend to use class 1 UE transmitting +31 dBm (max 1.25W). It was felt that this feature could be beneficial for some TDD bands that do not have to worry about backward compatibility. One such band, pushed by Sprint was TDD Band 41 (2500MHz). As this band is for the commercial UE's, instead of class 1, class 2 power at +26dBm (max 400mW) was proposed.

    3GPP TS 36.886 provides the following justification:

    Currently, 3GPP has defined only Power Class UE 3 as the type of UE supported for TDD LTE band 41 operations. This definition was based on aligning TDD LTE Band 41 UE power classes with prior work in 3GPP related to other bands. However, it should be mentioned that 3GPP UE Power Class 3 definition (i.e. 23dBm) was mainly driven to ensure backward compatibility with prior technologies (i.e. GSM/UMTS) [2] so that network deployment topologies remain similar. Furthermore, maintaining the same power class UE definition (i.e. Class 3) as previous technologies would maintaining compliance with various national regulatory rulings, particularly in terms of SAR, for FDD LTE duplexing mode. 

    However, TDD LTE band 41 does not have any 3GPP legacy technologies associated with it, hence the backward compatibility consideration is not applicable in its case. Also, since band 41 is defined as a TDD LTE band, it is less susceptible to SAR levels that FDD LTE bands due to SAR definition. Therefore, defining a new UE power class with higher than 23dBm Tx power for TDD LTE Band 41 operations would not compromise any of 3GPP foundational work, while improving UE and network performance. It should also be mentioned that 3GPP has done similar work on other bands (i.e. band 14) when defining a higher power class UE, hence the concept presented in this document is a continuation of that process.

    The present document carries out a feasibility analysis for defining a UE Power class 2 (i.e. 26dBm) for operation on TDD LTE band 41. The document analyses current and future technological advancements in the area of UE RF front-end components and architectures that enable such definition while maintaining 3GPP specification and other regulatory bodies' requirements. It should be emphasized that this proposal only relates to single carrier UL operations on TDD band 41 (i.e. TM-1/2 modes) without affecting current 3GPP definition for UL carrier aggregation on band 41.

    As you can see from the tweet above, Sprint CEO is quite pleased with the HPUE. 

    SourceDiana Goovaerts

    Iain Gillott, iGR points out that HPUE applies to Sprint’s 2.5 GHz TDD network and associated spectrum, and the company claims up to 30 percent increase in cell cover from the new technology.  It should be noted that HPUE is a 3GPP standard that applies to the 2.5 GHz TDD band (Band 41) and is also to be used by China Mobile and Softbank.  HPUE was developed as part of the Global TDD LTE Initiative (GTI) which includes Qualcomm Technologies, Samsung, ZTE, Broadcom, MediaTek, Skyworks Solutions, Alcatel, Motorola, LG and Qorvo... The cool part: the improvement in coverage comes from simply improving the device uplink power.  So Sprint, China Mobile and Softbank will not have to visit their cell sites to make changes; they just need 2.5 GHz TDD devices with HPUE to get the benefit.


    Milan Milanović recently wrote about Sprint’s Gigabit Class LTE network goes live in New Orleans. One of the questions I had was why is the uplink so rubbish as compared to downlink. He kindly pointed out to me that this is TDD config 2
    If you are wondering what is TDD Config 2, see the pic below
    Source: ShareTechNote

    Sprint expects HPUE to appear in postpaid devices starting in 2017, including new devices from Samsung, LG, HTC, and Moto. It’s expected that all of Sprint’s new devices will have HPUE support within the next two years.

    I think it would be interesting to see how this impacts when there are a lot more users and devices. I am quite sure there will be more requests for HPUE in further TDD bands.

    Related Links:

    Sunday, 16 October 2016

    Inside 3GPP Release-13 - Whitepaper by 5G Americas


    The following is from the 5G Americas press release:

    The summary offers insight to the future of wireless broadband and how new requirements and technological goals will be achieved. The report updates Release 13 (Rel-13) features that are now completed at 3GPP and were not available at the time of the publication of a detailed 5G Americas report, Mobile Broadband Evolution Towards 5G: 3GPP Release 12 & Release 13 and Beyond in June 2015.
    The 3GPP standards have many innovations remaining for LTE to create a foundation for 5G.  Rel-12, which was finalized in December 2014, contains a vast array of features for both LTE and HSPA+ that bring greater efficiency for networks and devices, as well as enable new applications and services. Many of the Rel-12 features were extended into Rel-13.  Rel-13, functionally frozen in December 2015 and completed in March 2016, continues to build on these technical capabilities while adding many robust new features.
    Jim Seymour, Principal Engineer, Mobility CTO Group, Cisco and co-leader of the 5G Americas report explained, “3GPP Release 13 is just a peek behind the curtain for the unveiling of future innovations for LTE that will parallel the technical work at 3GPP on 5G. Both LTE and 5G will work together to form our connected future.”
    The numerous features in the Rel-13 standards include the following for LTE-Advanced:
    • Active Antenna Systems (AAS), including beamforming, Multi-Input Multi-Output (MIMO) and Self-Organizing Network (SON) aspects
    • Enhanced signaling to support inter-site Coordinated Multi-Point Transmission and Reception (CoMP)
    • Carrier Aggregation (CA) enhancements to support up to 32 component carriers
    • Dual Connectivity (DC) enhancements to better support multi-vendor deployments with improved traffic steering
    • Improvements in Radio Access Network (RAN) sharing
    • Enhancements to Machine Type Communication (MTC)
    • Enhanced Proximity Services (ProSe)
    Some of the standards work in Rel-13 related to spectrum efficiency include:                                                                                                                       
    • Licensed Assisted Access for LTE (LAA) in which LTE can be deployed in unlicensed spectrum
    • LTE Wireless Local Area Network (WLAN) Aggregation (LWA) where Wi-Fi can now be supported by a radio bearer and aggregated with an LTE radio bearer
    • Narrowband IoT (NB-IoT) where lower power wider coverage LTE carriers have been designed to support IoT applications
    • Downlink (DL) Multi-User Superposition Transmission (MUST) which is a new concept for transmitting more than one data layer to multiple users without time, frequency or spatial separation
    “The vision for 5G is being clarified in each step of the 3GPP standards. To understand those steps, 5G Americas provides reports on the developments in this succinct, understandable format,” said Vicki Livingston, Head of Communications for the association.

    The whitepaper as follows:



    Related posts:

    Sunday, 22 May 2016

    QCI Enhancements For Mission Critical Communications

    Its been quite a while since I posted about QCI and end-to-end bearer QoS in EPC. In LTE Release-12 some new QCI values were added to handle mission critical communications.


    This picture is taken from a new blog called Public Safety LTE. I have discussed about the Default and Dedicated bearers in an earlier post here (see comments in that post too). You will notice in the picture above that new QCI values 65, 66, 69 & 70 have been added. For mission critical group communications new default bearer 69 would be used for signalling and dedicated bearer 65 will be used for data. Mission critical data would also benefit by using QCI 70.


    LTE for Public Safety that was published last year provides a good insight on this topic as follows:

    The EPS provides IP connectivity between a UE and a packet data network external to the PLMN. This is referred to as PDN connectivity service. An EPS bearer uniquely identifies traffic flows that receive a common QoS treatment. It is the level of granularity for bearer level QoS control in the EPC/E-UTRAN. All traffic mapped to the same EPS bearer receives the same bearer level packet forwarding treatment. Providing different bearer level packet forwarding treatment requires separate EPS bearers.

    An EPS bearer is referred to as a GBR bearer, if dedicated network resources related to a Guaranteed Bit Rate (GBR) are permanently allocated once the bearer is established or modified. Otherwise, an EPS bearer is referred to as a non-GBR bearer.

    Each EPS bearer is associated with a QoS profile including the following data:
    • QoS Class Identifier (QCI): A scalar pointing in the P-GW and eNodeB to node-specific parameters that control the bearer level packet forwarding treatment in this node.
    • Allocation and Retention Priority (ARP): Contains information about the priority level, the pre-emption capability, and the pre-emption vulnerability. The primary purpose of the ARP is to decide whether a bearer establishment or modification request can be accepted or needs to be rejected due to resource limitations.
    • GBR: The bit rate that can be expected to be provided by a GBR bearer.
    • Maximum Bit Rate (MBR): Limits the bit rate that can be expected to be provided by a GBR bearer.

    Following QoS parameters are applied to an aggregated set of EPS bearers and are part of user’s subscription data:
    • APN Aggregate Maximum Bit Rate (APN-AMBR): Limits the aggregate bit rate that can be expected to be provided across all non-GBR bearers and across all PDN connections associated with the APN.
    • UE Aggregate Maximum Bit Rate (UE-AMBR): Limits the aggregate bit rate that can be expected to be provided across all non-GBR bearers of a UE. The UE routes uplink packets to the different EPS bearers based on uplink packet filters assigned to the bearers while the P-GW routes downlink packets to the different EPS bearers based on downlink packet filters assigned to the bearers in the PDN connection.

    Figure 1.5 above shows the nodes where QoS parameters are enforced in the EPS system.

    Related links:



    Friday, 28 August 2015

    MCPTT Off-network and UE to UE/Network Relays

    3GPP SA6 recently held a workshop on Mission Critical Push To Talk (MCPTT) stage 3 development in Canada. You can look at the meeting report here and download any presentations from here.

    An interesting presentation that caught my attention was one on "MCPTT Off-network Architecture". The presentation is embedded below where it is described technically what is meant by Off-network. From my understanding an off-network from MCPTT point of view is one where the UE does not have network coverage.

    In such a situation a UE can connect to another UE that can connect to UE/network (if available) to relay the message. Its similar to another technology that I have talked about, Multihop Cellular Networks and ODMA. Anyway, here is the presentation:



    Sometimes the standards can take too long to develop a feature and apps can come and deliver a similar service at a very short notice. One such App that does something similar is called Firechat, which played a big role in many protests worldwide. The video explaining it below is worth watching.


    The problem with Apps is that they cannot be used by the emergency services or other governmental organisations, unless a standard feature is available. This is the expectation from this Off-network relays. It would work in combination with D2D/ProSe.


    For anyone interested in the latest Public Safety (PS), here is a presentation by SA6 chairman from July

    Sunday, 26 July 2015

    LTE vs TETRA for Critical Communications

    Sometime back I was reading this interview between Martin Geddes and Peter Clemons on 'The Crisis in UK Critical Communications'. If you haven't read it, I urge you to read it here. One thing that stuck out was as follows:

    LTE was not designed for critical communications.

    Commercial mobile operators have moved from GSM to UMTS to WCDMA networks to reflect the strong growth in demand for mobile data services. Smartphones are now used for social media and streaming video. LTE technology fulfils a need to supply cheap mass market data communications.

    So LTE is a data service at heart, and reflects the consumer and enterprise market shift from being predominantly voice-centric to data-centric. In this wireless data world you can still control quality to a degree. So with OFDM-A modulation we have reduced latency. We have improved how we allocate different resource blocks to different uses.

    The marketing story is that we should be able to allocate dedicated resources to emergency services, so we can assure voice communications and group calling even when the network is stressed. Unfortunately, this is not the case. Even the 3GPP standards bodies and mobile operators have recognised that there are serious technology limitations.
    This means they face a reputational risk in delivering a like-for-like mission-critical voice service.

    Won’t this be fixed by updated standards?
    The TETRA Critical Communications association (TCCA) began to engage with the 3GPP standards process in 2012. 3GPP then reached out to peers in the USA and elsewhere: the ESMCP project here in the UK, the US FirstNet programme, and the various European associations.

    These lobbied 3GPP for capabilities specifically aimed at critical communications requirements. At the Edinburgh meeting in September 2014, 3GPP set up the SA6specification group, the first new group in a decade.

    The hope is that by taking the critical communications requirement into a separate stream, it will no longer hold up the mass market release 12 LTE standard. Even with six meetings a year, this SA6 process will be a long one. By the end of the second meeting it had (as might be expected) only got as far as electing the chairman.

    It will take time to scope out what can be achieved, and develop the critical communications functionality. For many players in the 3GPP process this is not a priority, since they are focusing solely on mass market commercial applications.

    Similar point was made in another Critical communications blog here:

    LTE has emerged as a long term possible replacement for TETRA in this age of mobile broadband and data. LTE offer unrivalled broadband capabilities for such applications as body warn video streaming, digital imaging, automatic vehicle location, computer-assisted dispatch, mobile and command centre apps, web access, enriched e-mail, mobile video surveillance apps such as facial recognition, enhanced Telemetry/remote diagnostics, GIS and many more. However, Phil Kidner, CEO of the TCCA pointed out recently that it will take many LTE releases to get us to the point where LTE can match TETRA on key features such as group working, pre-emptive services, network resilience, call set-up times and direct mode.
    The result being, we are at a point where we have two technologies, one offering what end users want, and the other offering what end users need. This has altered the discussion, where now instead of looking at LTE as a replacement, we can look at LTE as a complimentary technology, used alongside TETRA to give end users the best of both worlds. Now the challenge appears to be how we can integrate TETRA and LTE to meet the needs and wants of our emergency services, and it seems that if we want to look for guidance and lessons on the possible harmony of TETRA and LTE we should look at the Middle East.
    While I was researching, I came across this interesting presentation (embedded below) from the LTE World Summit 2015





    The above is an interesting SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis for TETRA and LTE. While I can understand that LTE is yet unproven, I agree on the lack of spectrum and appropriate bands.

    I have been told in the past that its not just the technology which is an issue, TETRA has many functionalities that would need to be duplicated in LTE.



    As you can see from this timeline above, while Rel-13 and Rel-14 will have some of these features, there are still other features that need to be included. Without which, safety of the critical communication workers and public could be compromised.

    The complete presentation as follows. Feel free to voice your opinions via comments.


    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. 

    Thursday, 18 September 2014

    Update on Public Safety and Mission Critical communications

    Its been a while since I wrote about Public Safety and Mission Critical communications, so here is a quick summary.


    Iain Sharp have a good overview of whats happening in the standards in the LTE World Summit back in June. Embedded below is his complete presentation.



    There is another slightly older presentation that I also thought was worthwhile adding here.

    There is a lot of discussion centred around the use of commercial networks for mission critical communications, mainly die to cost. While this may make sense to an extent, there should be procedures put in place to give priority to public safety in case of emergency.



    We are planning to run a one day training in Jan 2015 on public safety. If this is of interest to you then please get in touch with me for more details.

    x-o-x-o-x-o-x-o-x-o-x-o-x
    After the post someone brought these links to my attention so I am adding them below:

    Thursday, 10 July 2014

    Taking 5G from vision to reality

    This presentation by Moray Rumney of Agilent (Keysight) in Cambridge Wireless, Future of Wireless International conference takes a different angle at what the targets for different technologies have been and based on that what should be the targets for 5G. In fact he has an opinion on M2M and Public safety as well and tries to combine it with 5G. Unfortunately I wasnt at this presentation but from having heard Moray speak in past, I am sure it was a thought provoking presentation.



    All presentations from the Future of Wireless International Conference (FWIC) are available here.

    Monday, 23 September 2013

    Push to talk (PTT) via eMBMS


    I was talking about push to share back in 2007 here. Now, in a recent presentation (embedded below) from ALU, eMBMS has been suggested as a a solution for PTT like services in case of Public safety case. Not sure if or when we will see this but I hope that its sooner rather than later. Anyway, the presentation is embedded below. Feel free to add your comments: