Patent Publication Number: US-2016242208-A1

Title: Data transmission from mobile radio communications device

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a National Stage Entry of International Application No. PCT/JP2014/005247, filed Oct. 16, 2014, which claims priority from GB 1318441.1, filed Oct. 18, 2013. The entire contents of the above-referenced applications are expressly incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to data transmission from a mobile radio communications device, such as those commonly referred to as User Equipment (UE) according to 3GPP (3rd Generation Partnership Project) specifications and scenarios, including devices involved in Machine Type Communication (MTC), requiring the transmission of small amounts of data, and commonly known as Small Data Transmission (SDT) features. 
     BACKGROUND ART 
     It is well known for example, that many MTC applications send or receive small amounts of data. Also there has been a large increase in smartphone use where many applications exchange ‘keep-alive’ messages with the network and seeking to keep network connections open. All this can lead to inefficient use of resources within 3GPP systems. 
     Indeed, the 3GPP Services and System Aspects (SA1) Working Group has identified SDT as a potentially important feature of MTC. According to section 7.2.5 of Technical Specification TS 22.368, the “MTC Feature SDT” is intended for use with MTC devices that send or receive small amounts of data and the system is required to support transmissions, either sending or receiving, of small amounts of data with minimal network impact (e.g. signalling overhead, network resources, delay for reallocation). Before transmission of small amount of data, the MTC Device may be attached or detached to/from the network and the system can also be arranged to count the number of small data transmissions per subscription such as for example for charging or statistical purposes. 
     The 3GPP SA2 Working Group has also considered SDT optimization (including in the context of keep-alive messages from smartphones) as part of the MTCe-SDDTE (Small Data transmission and Device Triggering Enhancements) Work Item, such as noted in section 5.1 in Technical Report TR 23.887. Here, it is noted that many MTC applications send or receive small amounts of data and which characteristic may lead to inefficient use of resources in the 3GPP system and so there is a corresponding device to improve efficiency. The exact amount that is considered to be small may differ between individual systems. 
     Further, this Work Item notes that, for SDT, it is assumed that data transfer can arise at any time required by the application. As above, before the transmission of the small data, the MTC device may be attached to, or detached from, the network. 
     In identifying “Efficient Small Data transmission” as a potentially important issue. 
     SA2 Working Group has proposed several solutions for the efficient use of SDT features and as clarified in the above mentioned Technical Report TR 23.887. 
     In general for SDT, a different data path from that normally used is proposed in order to reduce the network impact such as signalling overhead, network resources consumption and/or delay for reallocation etc. 
     It is generally arranged that this SDT feature is employed when particular criteria for the SDT are fulfilled. Examples of such criteria could be that the data to be transferred comprises just one IP (Internet Protocol) packet and, if it is necessary, an expected response is also one IP packet; or alternatively, that the data size is small. The observed size of many of the instances of data exchanges is on the order of 1K (1024) octets and as noted in the above technical specification TS 22.368 at section 7.2.5. 
     While the 3GPP SA2 Working Group has therefore sought to define and recommended solutions for SDT, there are still undecided issues related to how to control the use of SDT at both the UE and the network sides. For example, the following “Editor&#39;s Note” appears in Technical Report TR 23.887, at section 5.1.1.3.1.1 where it is reported that “How to ensure that the application correctly uses the Service Request procedure and does not abuse this ‘Small Data’ NAS (Non-Access Stratum) procedure is an open issue”. 
     It is clear from this “Editor&#39;s Note” that 3GPP systems need to employ solutions for restriction and control of the Small Data Transmission use by the UE and Applications (Apps) on the UE. 
     Also, there is a Small Data Transmission related Liaison Statement (LS) R2-133033 (NPL 1) from 3GPP RAN 2 Working Group in which it is acknowledged that benefits can arise from differentiated treatment of SDT in certain conditions. However, RAN2 Working Group also notes that should the SDT feature and solution be defined, it would be important to ensure that only traffic matching SDT characteristics makes use of such a solution, since the use of the SDT feature with other traffic patterns would result in capacity and performance loss. 
     That is, RAN2 notes that the solutions could lead to noticeable performance improvements on both the radio and the S1-MME interfaces only in very specific use cases, specifically only when the following conditions are fulfilled. First, that the solution is used for the transmission of ‘isolated’ bursts of packets, which means that the transmission of a bursts of packets is followed by a relatively long inactivity period (e.g. at least one minute). If the inter-arrival time of the packet bursts is shorter, then this solution would offer worse capacity than legacy solutions as it is more efficient to keep the UEs in RRC (Radio Resource Control) connected mode. Secondly, that the packet burst is made of maximum 2 packets (in total, i.e. considering both UL (Uplink) and DL (Downlink) packets). If more packets are sent in a burst, the solution would again offer worse capacity than legacy solutions on both the radio and the S1-MME interfaces (as this would require the set up/release of a RRC connection for each packet pair). Thirdly, that the packets are ‘small’ in size (e.g. in the order of hundreds of bytes)—(i.e. &gt;1 Kbytes per UL/DL message) otherwise the gain over the radio interface would be lost. Although there would be a reduction in the number of messages on the S1-MME interface, there would be an increase in the size of such 51 messages. 
     It is suggested in Technical Report TR 23.887 that one possible way to achieve SDT restriction and control is via a subscription requirement for SDT. In section s5.1.1.3.1.2 of this Technical Report there is the following expected impact on the Home Subscriber Server (HSS) from SDT deployment, i.e. “Possible subscription information to indicate if UE uses “small data feature”. It is also thought possible that network operators and MTC service providers might agree in the future the provision of SDT subscription services for some MTC services that match the traffic pattern for small data (and as defined and standardized by the 3GPP in the future or defined by the network operators themselves). One possible example that could qualify for SDT is utility (gas/electricity) meter reporting. Another example could be remote reporting in the health field (e-health). These examples are of course not exhaustive. In such an environment, a SDT capable UE (or MTC device) would likely exhibit multiple applications (each with a SDT subscription) and with an access to the Small Data Service that might be controlled/restricted by way of subscription. 
     CITATION LIST 
     Non Patent Literature 
     
         
         NPL 1: 3GPP TSG RAN WG2 Meeting #83, R2-133033, “Reply LS on requesting further input on MTCe solution 5.1.2.3.1”, 2013-08 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the inventors of this application have found that such known means of seeking to maintain and control SDT functionality are disadvantageously limited. 
     The present invention seeks to provide for a mobile radio communications device and method of operation, having advantages over known such devices and methods when considering the adoption of a SDT feature, and also to related network devices, and related methods of operation and overall networks systems and methods of operation. 
     Solution to Problem 
     According to a first exemplary aspect of the present invention, there is provided a mobile radio communications device for communication within a mobile radio communications network, the device being arranged for operation with at least one Application requiring network access for data transmission, and network access including a Small Data Transmission feature, the device further being arranged to hold Application information by means of which it can be determined if an Application seeking network access can employ the Small Data Transmission feature for its data transmission. 
     The invention can prove particularly advantageous in offering an improved control/restriction of the adoption of SDT features as compared with that currently known and, in particular, that rely on subscription services/information. In particular, it can found that the network can have an improved mechanism to deter or control the User Equipment for use of an SDT feature. 
     Advantageously, the device can be arranged to determine if the required transmission meets Small Data Transmission criteria. In particular, such determination can be achieved at the application layer, or a lower layer, such as protocol stack, within the device. 
     In one aspect, the Application information allows identification of those Applications that can employ the Small Data Transmission feature. In particular, such application information can be provided in the form of an SDT Allowed Applications List. 
     Alternatively, the said Application information can be provided so as to identify those Applications that are barred from using the Small Data Transmission feature and, as such, can be provided in the form of a SDT Barred Application List. 
     The device can further be arranged such that, if by reference to the Application information it is determined that the Small Data Transmission feature cannot be employed, a fall-back packet transmission procedure can be employed. 
     As a further feature, the device can be arranged to receive the Application information from the radio communications network. 
     In particular the Application information can be delivered by way of Home Subscriber Server (HSS) and, if required, as subscriber information. As another example, the Application information can be delivered during any NAS procedures such as an Attach/Tracking Area Update (TAU)/Routing Area Update (RAU) procedure. 
     Also, if required, the Application information can be delivered by way of a provisioning mechanism, such as Open Mobile Alliance Device Management OMA DM or Universal Subscriber Identity Module-Over the Air (USIM OTA) mechanisms. 
     Yet further, the device can be arranged to determine within its application layer if an Application seeking network access can employ the Small Data Transmission feature. 
     Alternatively, the device can be arranged to determine in its protocol stack if the Application seeking network access can employ the Small Data Transmission feature. 
     In one particular embodiment, the said Application information, can comprise an Application identifiers. 
     It should be appreciated that within the present invention as noted above, the said at least one Application can comprise an Application derived internally of the device, e.g. on the UE device. Alternatively, the said at least one Application can comprise an Application derived externally of the device and so which effectively employs the UE as a modem type device, for example for Applications from sensors or devices external to the UE and connected for example by AT commands, Bluetooth or any other appropriate interface technology. 
     According to another exemplary aspect of the present invention there is provided a method of operation within a mobile radio communications device for communication within a mobile radio communications network, the device including at least one application requiring network access for data transmission and the network access including a small data transmission feature, the method including the step of determining by means of reference Application information if an Application seeking network access can employ the small data transmission feature for its data transmission. 
     The method can further include the step of determining if the required transmission meets small data transmission criteria. Such determining step can be conducted within the application layer, or at a lower layer of the mobile radio communications device such as its protocol stack. 
     The method can further include presenting the reference Application information as an identification of those applications that are allowed access to a small data transmission feature, such as by means of an SDT Allowed Applications List, or applications that are not allowed access to a small data transmission feature, such as a SDT Barred Applications List. 
     The operational method within the mobile radio communications device can include the packet transmission of the application data by way of a fall-back procedure if it is determined that the required transmission does not meet the Small Data Transmission requirements, or if it is determined that the application is not identified as one that is permitted access to the Small Data Transmission feature. 
     The method further includes receiving the reference Application information from the network. 
     As noted above, the said reference Application information can be received by way of HSS as subscription information, or delivered during any NAS procedures such as an Attach/TAU/RAU procedure. 
     Also, the method can include receipt of the reference Application information by way of a provision mechanism such as OMA DM or USIM OTA mechanisms. 
     Preferably, the step of determining whether or not the application is barred or allowed, is advantageously conducted in the application layer. Alternatively, such determination can also be conducted within the lower layers of the device, such as in the protocol stack. 
     As appreciated from the above, the said reference Application information can comprise application identifiers. 
     According to another exemplary aspect of the present invention there is provided a mobile radio communications network device arranged for communication with a mobile radio communications device operating within a mobile radio communications network and arranged for operation with at least one Application requiring network access for data transmission, such network access including a Small Data Transmission feature, the device further being arranged to deliver reference Application information to the mobile radio communications device by means of which it can be determined at the mobile radio communications device if an application seeking network access can employ the Small Data Transmission feature for its data transmission. 
     The reference application information can advantageously comprise an indication of those applications that are allowed access to the Small Data Transmission feature or, alternatively, an indication of those applications that are not allowed access to a Small Data Transmission feature. 
     As such, the reference Application information can be presented to the mobile radio communications device as an Allowed Applications List, or a Barred Applications List. 
     The mobile radio communications network device is further arranged to deliver the Application information by way of a HSS as, for example, subscription information. 
     As a further option the Application Information can be delivered during any NAS procedures such as an Attach/TAU/RAU procedure or by way of a provisioning mechanism such as a OMA DM or USIM OTA mechanism. 
     It should be appreciated that the mobile radio communications network device can comprise any appropriate network device such as, for example an HSS, MME, or eNodeB (evolved Node B) all of which can be arranged, in series combination, to deliver this information to the mobile radio communications device. 
     According to a related further exemplary aspect of the present invention, there is provided a method of operation within a mobile radio communications network device arranged to communicate with a mobile radio communications device within the mobile radio communications network, and arranged for operation with at least one Application requiring network access for data transmission, the network access including a Small Data Transmission feature, the method including delivering reference Application information to the mobile radio communications device by means of which it can be determined at the mobile radio communications device if the application seeking network access can employ the Small Data Transmission feature for its data transmission. 
     The method can include the step of delivering reference Application information comprising an indication of those applications that are allowed access to the Small Data Transmission feature or, alternatively, providing an indication of those applications that are barred from employing the Small Data Transmission feature. 
     The delivery of the said reference Application information can be achieved by way of a HSS such as, by way of subscription information, or can be delivered during any NAS procedures such as an Attach/TAU/RAU procedure. 
     A further alternative of this step is to provide the Application information by way of a provisioning mechanism such as OMA DM or USIM OTA mechanisms. 
     It will of course be appreciated that the present invention can also provide for a communications system employing a mobile radio communication device and a mobile radio communications network device as outlined above. 
     Also, the invention can provide for a method of operating a mobile radio communications network, including steps of operating a mobile radio communications device, and a mobile radio communications network device, as outlined above. 
     To summarise therefore, it should be appreciated that the present invention advantageously allows for the network to control, in the UE, the applications which can or cannot use the SDT features. This control can be achieved by reference to a SDT feature allowed applications list (SDT Allowed App List) or a SDT feature barred application list (SDT Barred App List). 
     The SDT feature can be used for the application data transfer when the application which starts the IP packet transfer is listed in the SDT Allowed App List. Otherwise the SDT feature cannot be used. 
     Or alternatively the SDT feature cannot be used for the application data transfer when the application which starts the IP packet transfer is listed in the SDT Barred App List. 
     The list shall be advantageously controlled from the network side. As noted above, it could be provisioned in HSS as subscription information. 
     Alternatively, the list can be delivered from network to the UE, for example during any NAS procedures such as an Attach/TAU/RAU procedure, or using provisioning mechanisms such as OMA DM or USIM OTA. 
     The list can then be stored in the UE so as to be held therein and used to decide whether or not that the use of the SDT feature is allowed for a particular application. Applications in the list can advantageously be specified by way of Application Identifiers. Any format can be defined for this purpose. For example, a similar format used by an Application port ID which is standardized by IANA (Internet Assigned Number Authority). 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to for example, provide for a mobile radio communications device and method of operation, having advantages over known such devices and methods when considering the adoption of a SDT feature, and also to related network devices, and related methods of operation and overall networks systems and methods of operation. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  comprises a signalling diagram illustrating signalling and connectivity in a mobile radio communications device and network devices during an attach procedure and so as to illustrate the incorporation of signalling and data transmission according to an exemplary embodiment of the present invention. 
         FIG. 2  comprises a schematic signalling diagram between a mobile radio communications device and a network device and including messaging within the mobile radio communications device according to one exemplary aspect of the present invention. 
         FIG. 3  comprises a schematic signalling diagram between a mobile radio communications device and a network device and including messaging within the mobile radio communications device according to another exemplary embodiment of the present invention. 
         FIG. 4  comprises a schematic signalling diagram between a mobile radio communications device and a network device and including messaging within the mobile radio communications device according to a yet further exemplary embodiment of the present invention. 
         FIG. 5  comprises a schematic signalling diagram between a mobile radio communications device and a network device and including messaging within the mobile radio communications device according to a still further exemplary embodiment of the present invention. 
         FIG. 6  comprises schematic representation of a mobile radio communications device ranged for operation according to an exemplary embodiment of the present invention. 
         FIG. 7  comprises a schematic representation of a mobile radio communications network device arranged for operation in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Exemplary embodiments of the invention will be described further hereinafter, by way of example only, reference to the accompanying drawings. 
     In  FIG. 1 , there is provided a signalling diagram based on Figure 5.3.2.1-1 known from 3GPP Technical Specification document TS 23.401 and concerning a “Network Attach” for a mobile radio communications device such as a UE arranged to register with the network to receive services that require such registration. 
     Such registration is described as Network Attachment and the “always-on” IP connectivity for UE/users of the Evolved Packed System (EPS) is enabled by establishing a default EPS bearer during Network Attachment. The Policy and Charging Control (PCC) rules applied to the default EPS bearer may be predefined in the Packet Data Network Gateway (PDN GW) and activated in the attachment by the PDN GW itself. The Attach procedure may trigger one or multiple dedicated bearer establishment procedures to establish dedicated EPS bearer(s) for that UE. During the attach procedure, the UE may request for an IP address allocation. Terminals utilising only IETF (Internet Engineering Task Force) based mechanisms for IP address allocation are also supported. 
     During the Initial Attach procedure, the Mobile Equipment Identity (MEI) is obtained from the UE. The Mobile Management Entity (MME) operator may check the MEI with an Equipment Identity Register (EIR). The MME passes the ME Identity (IMEISV) to the HSS and to the PDN GW. Also, if the MME supports SRVCC (Single Radio Voice Call Continuity), the MME can inform the HSS with the UE SRVCC capability e.g. for further IMS registration. 
     The E-UTRAN (Evolved Universal Terrestrial Radio Access Network) Initial Attach procedure is used for Emergency Attach by UEs that need to perform emergency services but cannot gain normal services from the network. These UEs are in limited service state as defined in Technical Specification TS 23.122. Also UEs that had attached for normal services and do not have emergency bearers established and are camped on a cell in limited service state (e.g. restricted Tracking Area or not allowed CSG (Closed Subscriber Group)) shall initiate the Attach procedures indicating that the attach is to receive emergency services. UEs that camp normally on a cell, i.e. UEs that are not in limited service state, should initiate normal initial attach when not already attached and shall initiate the UE Requested PDN Connectivity procedure to receive emergency EPS bearer services. 
     Turning now to the detail of  FIG. 1 , the actual signalling as arising as between a UE  12 , eNodeB  14 , MME  16 , MME/Serving GPRS (General Packet Radio Service) Support Node SGSN  18 , Serving GW  20 , PDN GW  22 , Policy and Charging Rules Function (PCRF)  24 , HSS  26  and EIR  28  is illustrated and those aspects not directly relevant to the present invention can be summarised as follows. 
     As noted, the signalling relates to an Attach procedure during the initial stages A of which a mobile equipment identify is obtained from the UE  12  and which can be checked by way of the EIR  28 . 
     The session request/response/termination signalling B and C arises prior to delivery of an update location acknowledgement signal  30  from the HSS  24  to the MME  16  in accordance with an embodiment of the present invention, it is at the time of this signal that the network first commences delivery of reference Application information seeking to identify those Applications (Apps) which are to be allowed access to a Small Data Transmission feature. In this particular embodiment, such reference Application information comprises a Small Data Transmission Allowed or Small Data Transmission Barred, App list. 
     Signalling relating to the session request/response arises as shown D between the MME  16  and the Serving GW  20  and subsequent to this, an initial context setup request signal  32  which contains the Attach Accept message is delivered from the MME  16  to the eNodeB  14  of the network. This Attach Accept message then provides for onward delivery of the Small Data Transmission Allowed or Small Data Transmission Barred Apps list previously received at the MME  16  from the HSS  26 . 
     To complete the delivery process to the UE  12 , an RRC connection reconfiguration signal  32  which contains the Attach Accept message is delivered from the eNodeB  14  to the UE  12  provided as part of the Attach accept procedure as known from the above mentioned tactical specification TS 23.401. However, in this aspect of the invention, the Attach Accept message in the signal  32  contains a Small Data Transmission Allowed or Small Data Transmission Barred App list as previously received from the MME  16 . 
     The UE  12  then stores  36  the received allowed/barred list for the control of Apps therein and which might be seeking use of the Small Data Transmission feature. 
     For completeness, concluding signalling E is shown and which comprises RRC connection reconfiguration complete, and attach complete signalling prior to the provision of first uplink data, any required modified bearer requests/responses and also first downlink data. 
     The manner in which the UE  12  employs the reference Application information, comprising for example, either the SDT Allowed App List or SDT Barred App List can vary as required and various examples are discussed further hereinafter. 
     Turning now to  FIG. 2 , there is provided a schematic representation of signalling arising both within the UE  12 , and to a network device  17  illustrated in this example as the eNodeB  14  and MME  16  of  FIG. 1 . 
     Within the UE  12  there is illustrated its application layer  38  and the protocol stack  40  and the procedure commences with a particular App requesting, by way of signal  42 , to the protocol stack  40  as is currently known, IP packet transmission. 
     In this illustrated example, the protocol stack  40  is arranged to check  44  first whether or not the required transmission fulfils the Small Data Transmission criteria, for example due to its size, and secondly whether or not the App is included within a Small Data Transmission Allowed App List held in the UE  12  and as previous received from the network device  16 . 
     It is then determined within the protocol stack  40  that the App can employ the Small Data Transmission feature if the IP packet concerned not only fulfils the small data transmission criteria, but that the App itself is identified as one appearing in the Small Data Transmission Allowed App List. If both requirements are not fulfilled the protocol stack can be arranged to determine that a fall-back, i.e. usual, packet transmission procedure be employed for the Apps transmission requirements. 
     That is, when the protocol stack decides that the SDT can be employed, it is determined at  46  that use can be made of the small data transmission procedure such as that proposed in Technical Report TR 23.887 s5.1.1. 
     If it is determined at the protocol stack that the Small Data Transmission feature cannot be employed  48 , then a standard normal packet transmission procedure is employed as outline above. 
     As an alternative, rather than employing a Small Data Transmission Allowed App List, the invention can provide for the delivery and storage of a Small Data Transmission Barred App List and its adoption within the protocol stack as illustrated with reference to  FIG. 3 . Of course, in this case, appearance of the particular App within the Barred App List, will prevent it achieving network access by way of the small data transmission feature. 
     With particular reference therefore to  FIG. 3 , there is provided a schematic illustration of signalling arising within, and from, a UE  12  such as that illustrated in  FIG. 1 , and in relation to a network device  17  again such as an eNodeB  14  and MME  16  as illustrated in  FIG. 1 . 
     As with the embodiment of  FIG. 2 , and in accordance with existing data transfer request, any particular application within the application layer  38  of the UE  12  can send a data transfer request  50  to the protocol stack  40  seeking transmission of the relevant IP packet. 
     Within the protocol stack  40 , it is determined  52  how uplink data from the application  38  should be handled. Thus, it is first determined whether or not the App requiring transmission as identified in the application layer  38  fulfils the small data transmission criteria, and secondly, whether or not the particular application identified is included within the Small Data Transmission Barred App List as stored in the UE  12  and as previously received from the network. 
     If, within the protocol stack  40 , it is determined  54  that the IP packet fulfils the Small Data Transmission criteria and does not appear in the Small Data Transmission Barred App List, then the small data transmission procedure, such as that of technical report TR 23.887 s5.1.1 can be employed or transmission of the IP packet to the network device  17 . 
     However, if it is either determined that the IP packet does not fulfil the Small Data Transmission criteria, or it is determined that the App appears in the Small Data Transmission Barred App List, adoption of the Small Data Transmission feature will not be allowed and transmission of the IP packet is only allowed by way of a normal/standard packet transmission procedure  56 . 
     As an alternative to having the determination concerning possible use of a Small Data Transmission feature made within the protocol stack, it is also possible that such determination be made elsewhere within the device such as in the application layer  38  as illustrated further in, and discussed with reference to,  FIGS. 4 and 5 . 
     Turning first to  FIG. 4 , there is illustrated an embodiment in which the determination of the availability of the small data transmission feature to a particular application is made in the application layer  38  and by reference to a Small Data Transmission Allowed App List in the UE  12  and as previously delivered from the network. 
     Also, the initial determination  58  as to how the required uplink data should be handled is made within the application layer  38  where it is first determined whether or not the IP packet fulfils the Small Data Transmission criteria and whether it appears in the Small Data Transmission Allowed App List. 
     If both requirements are fulfilled, a small data transfer request  60  is delivered from the application layer  38  to the protocol stack  40  such that onward data transmission to the network  62  can continue in accordance with a small data transmission procedure such as that known from TR 23.887 s5.1.1. 
     Alternatively, if it is determined that the IP packet does not fulfil the small data transmission criteria, or the application is not in the SDT Allowed App List, then a default/normal data transfer request  64  is delivered from the application layer  38  to the protocol stack  40  so as to allow for a normal packet transmission procedure  66  between the UE  12  and the network device  17  again such as an eNodeB  14  and MME  16  of  FIG. 1 . 
     Referring now to  FIG. 5 , this example is similar to  FIG. 4  insofar as the determination of the suitability of the IP packet for transmission to the network by way of a small data transmission procedure as determined in the application layer  38  of the UE  12 . However, in this instance, such determination is made by reference to a small data transmission Barred App List, i.e. an indication of applications by way of reference Application information that should not be allowed access to the small data transmission feature. 
     There is again illustrated signalling within the UE  12 , and between a UE  12  and the network device  17  such as an eNodeB  14  and MME  16  of  FIG. 1  and in the application layer  38  determination is made  68  as to how the uplink data should be handled. 
     If, within the application layer  38 , it is determined that the IP packet seeking network access by the App fulfils the small data transmission criteria, again due for example to size and/or structure, and does not appear in the small data transmission Barred App List, a small data transfer request  70  for that IP packet is delivered from the application layer  38  to the protocol stack  40  for the onward transmission of the data to the network device  17  by way of a Small Data Transmission procedure  72  for example according to TR 23.887 s5.1.1. 
     However, if the IP packet from the application layer  38  does not fulfil the small data transmission criteria or the application appears in the small data transmission Barred App List, then a default/normal data transfer request for the IP packet  74  is delivered from the application layer  38  to the protocol stack  40 . The application data is then transmitted from the UE  12  by way of a default/normal packet transmission procedure  76 . 
     Turning now to  FIG. 6 , there is provided a schematic illustration of a mobile radio communications device such as a UE  78  arranged for operation in accordance with one aspect of the present invention and so as to provide for efficient control of access to, and use of, a Small Data Transmission feature for data transmissions to a network device. 
     The UE  78  includes standard transmission/reception functionality circuitry  80  operatively to connect to an antenna arrangement  82  and also an interface device  84  for allowing user interface with the UE  78 . 
     The UE  78  includes a controller  86  for controlling various aspects of functionality of the UE  78  in accordance with a standard layered configuration  88  of which the application  90  and lower layer such as protocol stack  92  are illustrated. The UE  78  also includes memory functionality  94  which, in accordance with the present invention, can be employed to store either or both, of a small data transmission Allowed App List, or a small data transmission Barred App List. These lists are employed as required either within the application layer  90  or protocol stack  92  to determine whether or not a particular application requiring network access should be allowed to employ a Small Data Transmission feature as discussed hereinbefore. 
     With regard to  FIG. 7 , there is provided a similar schematic diagram of a network device comprising an MME  96 , such as that 16 of  FIG. 1 , and having transmission/reception circuitry  98  operatively connected to an interface arrangement  100  and including control functionality  102  and an App List processor  104 . 
     In this illustrated example, the App List processor  104  is arranged to include the allowed/barred App list in the Attach/TAU/RAU accept message to be composed by the MME  96  for onward delivery to the eNodeB which serves as a relay device for onward delivery of the allowed/barred App list within RRC connection reconfiguration signalling to a UE such as the UE  78  illustrated with reference to  FIG. 6 . 
     Although the network device illustrated is functionally described as a MME, the device could readily comprise a combined network node including both MME and eNodeB functionality with the App List processor  104  provided within the MME part of the network device, and the eNodeB part again simply conveying the Attach/TAU/RAU accept message to the UE as a relay and without awareness of the App list. 
     In each case, the List processor seeks to incorporate the Allowed App List or the Barred App List into network signalling, such as the signalling arising as part of an Attach Procedure, for eventual delivery to, and storage in, the UE device. 
     Note that the present invention is not limited to the above-mentioned exemplary embodiments, and it is obvious that various modifications can be made by those of ordinary skill in the art based on the recitation of the claims. 
     This application is based upon and claims the benefit of priority from United Kingdom Patent Application No. 1318441.1, filed on Oct. 18, 2013, the disclosure of which is incorporated herein in its entirety by reference. 
     The whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes. 
     [Supplementary Note 1] 
     A mobile radio communications device for communication within a mobile radio communications network, the device arranged for operating at least one Application requiring network access for data transmission and the network access including a Small Data Transmission feature, the device further being arranged to receive reference Application information by means of which it can be determined if an application seeking network access can employ the Small Data Transmission feature for its data transmission. 
     [Supplementary Note 2] 
     The mobile radio communications device as claimed in Supplementary Note 1 and arranged to determine if the required transmission meets Small Data Transmission criteria. 
     [Supplementary Note 3] 
     The mobile radio communications device as claimed in Supplementary Note 2 and arranged such that it is determined in an application layer, or in a protocol stack of the device if the required transmission meets Small Data Transmission criteria. 
     [Supplementary Note 4] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 3, wherein the reference Application information allows identification of those applications that can employ the Small Data Transmission feature. 
     [Supplementary Note 5] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 4, wherein the reference application information allows identification of those applications that are barred from using the Small Data Transmission feature. 
     [Supplementary Note 6] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 5, and arranged such that if, by reference to the reference Application information, it is determined that the Small Data Transmission feature cannot be employed, if fall-back packet transmission procedure is employed. 
     [Supplementary Note 7] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 6, and arranged to receive the reference Application information from the radio communications network. 
     [Supplementary Note 8] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 7, and arranged to determine in its application layer if an Application seeking network access can employ the small data transmission feature. 
     [Supplementary Note 9] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 7, and arranged to determine in its protocol stack if an Application seeking network access can employ the small data transmission feature. 
     [Supplementary Note 10] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 9, wherein the said reference Application information comprises Application Identifiers. 
     [Supplementary Note 11] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 10, wherein the said at least one Application is derived internally of the device. 
     [Supplementary Note 12] 
     The mobile radio communications device as claimed in any one of Supplementary Notes 1 to 10, wherein the said at least one Application is derived externally of the device. 
     [Supplementary Note 13] 
     A method of operation within a mobile radio communications device for communication within a mobile radio communications network, the device including a plurality of applications requiring network access for data transmission and the network access including a small data transmission feature, a method including the step of determining by means of reference Application information if an Application seeking network access can employ the small data transmission feature for its data transmission. 
     [Supplementary Note 14] 
     The method as claimed in Supplementary Note 13 and including the step of determining if the required transmission meets small data transmission criteria. 
     [Supplementary Note 15] 
     The method as claimed in Supplementary Note 14 wherein the said determining step is conducted within an application layer, or protocol stack. 
     [Supplementary Note 16] 
     The method as claimed in any one of Supplementary Notes 13, 14 and 15, and including presenting the reference Application information as an identification of applications that are allowed access to the Small Data Transmission feature, or as an indication of applications that are not allowed access to the Small Data Transmission feature. 
     [Supplementary Note 17] 
     The method as claimed in any one of Supplementary Notes 13 to 16 and including transmission of the application data by way of a fall-back procedure if it is determined that the required transmission does not meet Small Data Transmission criteria, and/or if the application is not identified as one that is permitted access to the Small Data Transmission feature. 
     [Supplementary Note 18] 
     The method as claimed in any one of Supplementary Notes 13 to 17 and including the step of receiving the reference Application information from the network. 
     [Supplementary Note 19] 
     The method as claimed in any one of Supplementary Notes 13 to 18 and wherein the step of determining whether or not the application is barred or allowed, is conducted in the application layer. 
     [Supplementary Note 20] 
     The method as claimed in any one of Supplementary Notes 13 to 18 and wherein the step of determining whether or not the application is barred or allowed is conducted within the protocol stack. 
     [Supplementary Note 21] 
     The method as claimed in any one of Supplementary Notes 13 to 20 and wherein the said Application seeking network access is derived internally of the device. 
     [Supplementary Note 22] 
     The method as claimed in any one of Supplementary Notes 13 to 20 and wherein the said Application seeking network access is derived externally of the device. 
     [Supplementary Note 23] 
     A mobile radio communications network device arranged for communication with a mobile radio communications device operating within a mobile radio communications network and arranged for operation with Applications requiring network access for data transmission, such network access including a small data transmission feature, the device further being arranged to deliver reference Application information to the mobile radio communications device by means of which it can be determined if an application seeking network access can employ the small data transmission feature for its data transmission. 
     [Supplementary Note 24] 
     The mobile radio communications network device as claimed in Supplementary Note 23 wherein the said reference application information comprises an indication of those applications that are allowed access to the Small Data Transmission feature or an indication of those applications that are not allowed access to the Small Data Transmission feature. 
     [Supplementary Note 25] 
     The mobile radio communications network device as claimed in Supplementary Note 23 or 24 and arranged to present the reference Applications data to the mobile radio communications device as an allowed applications list, or a barred applications list. 
     [Supplementary Note 26] 
     The mobile radio communications network device as claimed in Supplementary Note 23, 24 or 25 and comprising any one of a Home Subscriber Server, Mobile Management Entity or eNobeB. 
     [Supplementary Note 27] 
     A method of operation within a mobile radio communications network device arranged to communicate with a mobile radio communications device created within the mobile radio communications network, and arranged for operation with Applications requiring network access for data transmission, the network access including a small data transmission feature, the method including delivering reference Application information to the mobile radio communications device by means of which it can be determined if the application seeking network access can employ the small data transmission feature for its data transmission. 
     [Supplementary Note 28] 
     The method as claimed in Supplementary Note 27 and including the step of delivering the reference application information comprising an indication of those applications that are allowed access to the Small Data Transmission feature. 
     [Supplementary Note 29] 
     The method as claimed in Supplementary Note 27 and including the step of delivering the reference application information comprising an indication of these applications that are barred from employing the Small Data Transmission feature. 
     [Supplementary Note 30] 
     A communications system employing a mobile radio communication device as claimed in any one of Supplementary Notes 1 to 12 and a mobile radio communications network device as claimed in any one of Supplementary Notes 23 to 26. 
     [Supplementary Note 31] 
     A method of operating a mobile radio communications network, including steps of operating a mobile radio communications device as claimed in any one of Supplementary Notes 13 to 20, and operating a mobile radio communications network device. 
     [Supplementary Note 32] 
     A mobile radio communications device substantially as hereinafter described with reference to the accompanying drawings. 
     [Supplementary Note 33] 
     A method of operation within a mobile radio communications device and substantially as hereinbefore described with reference to, the accompanying drawings. 
     [Supplementary Note 34] 
     A mobile radio communications network device substantially as hereinbefore described with reference to the accompanying drawings. 
     [Supplementary Note 35] 
     A method of operation within a mobile radio communications network device substantially as hereinbefore described with reference to the accompanying drawings. 
     [Supplementary Note 36] 
     A mobile radio communications system substantially as hereinbefore described with reference to the accompanying drawings. 
     [Supplementary Note 37] 
     A method of operation within a mobile radio communications system substantially as hereinbefore described with reference to the accompanying drawings. 
     REFERENCE SIGNS LIST 
     
         
           12 ,  78  UE 
           14  eNodeB 
           16 ,  96  MME 
           17  NETWORK DEVICE 
           18  MME/SGSN 
           20  Serving GW 
           22  PDN GW 
           24  PCRF 
           26  HSS 
           28  EIR 
           38 ,  90  APPLICATION LAYER 
           40 ,  92  PROTOCOL STACK 
           80  TRANSMISSION/RECEPTION FUNCTIONALITY CIRCUITRY 
           82  ANTENNA ARRANGEMENT 
           84  INTERFACE DEVICE 
           86  CONTROLLER 
           88  STANDARD LAYERED CONFIGURATION 
           94  MEMORY FUNCTIONALITY 
           98  TRANSMISSION/RECEPTION CIRCUITRY 
           100  INTERFACE ARRANGEMENT 
           102  CONTROL FUNCTIONALITY 
           104  App List PROCESSOR