Client Initiated Idle Mode Transition

Abstract

In accordance with some embodiments, a user equipment can initiate connected-to-idle mode transitions. A three way handshake is undertaken before allowing network disconnection. The transition can be made with a reasonable amount of signaling overhead.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Provisional Application Ser. No. 61/612,188, filed Mar. 16, 2012, hereby expressly incorporated by reference herein.

BACKGROUND

This relates generally to radio communications and, particularly, to cellular radio communications.

Many radio operated devices have an increasing number of applications that send only a small amount of data. The transmission frequency of such packets is relatively high. “Always on applications” include email, chat, instant messaging, stock updates, and weather updates. Thus, because of the frequency of transmission, power consumption may tend to be excessive.

There is a mechanism called fast dormancy that allows mobile devices to reduce their power consumption when they come to the decision that physical conductivity to the network is no longer required. Fast dormancy has been removed from the 3GPP standards for power saving purposes.

Embodiments may find application in a wireless local area network (WLAN) or a wireless wide area network (WWAN) including a WiMAX (Worldwide Interoperability for Microwave Access) network or the like. WiMAX technology is based on the IEEE 802.16 family of standards, including IEEE 802.16e, IEEE 802.16m, and others. Embodiments herein may also be applicable to other WWANs such as those operating according to 3GPP Long Term Evolution (LTE) or LTE-Advanced, or similar, follow-on wireless standards. Further, while several specific standards have been set forth herein as examples of suitable applications, implementations herein are not limited to any particular standard or protocol.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are described with respect to the following figures:

FIG. 1 is a schematic depiction of a user equipment according to one embodiment;

FIG. 2 is a flow chart for one embodiment; and

FIG. 3 is a depiction of medium access control control element for one embodiment.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the claimed invention. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention claimed may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In accordance with some embodiments, a user equipment can initiate connected-to-idle mode transitions. A three way or step handshake is undertaken before allowing network disconnection. The transition can be made with a reasonable amount of signaling overhead.

As shown in FIG. 1, the user equipment 10 may include a radio frequency antenna 12, coupled to a transceiver 14. The transceiver 14, in turn, is coupled to a processor 16, which may be an application processor or a digital signal processor. The processor 16 is coupled to a storage 18. The storage 18 may include an uplink buffer 20 and a downlink buffer 22.

In some implementations, the processor 16 can be a single processing unit or a number of processing units, all of which may include multiple computing units or multiple cores. The processor 16 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor 16 can be configured to fetch and execute processor-executable instructions stored in the storage 18, respectively, or other processor-readable storage media.

The storage 18 can include any processor-readable storage media known in the art including, for example, volatile memory (e.g., RAM) and/or non-volatile memory (e.g., flash, etc.), mass storage devices, such as hard disk drives, solid state drives, removable media, including external drives, removable drives, floppy disks, optical disks, or the like, or any combination thereof. The storage 18 may store computer-readable processor-executable program instructions as computer program code that can be executed by the processor 16 as a particular machine for carrying out the methods and functions described in the implementations herein. Further, storage 18 may also include other program modules stored therein and executable by processor 16 for carrying out implementations herein, such codecs, or the like.

Additionally, transceiver 14 may be implemented in a variety of devices and systems, such as cellular communications systems, Wi-Fi systems, or the like. For example, transceiver 14 might be incorporated in a mobile computing device, such as a cell phone, smart phone, laptop, wireless access point, a second computing device, or the like, or vice versa. Further, while exemplary system architectures have been described, it will be appreciated that other implementations are not limited to the particular system architectures described herein. For example, the techniques and architectures described herein may be incorporated in any of a variety of wireless communication devices, and implementations herein are not limited to any type of communication devices.

In the downstream or downlink case, the user equipment 10 may communicate with devices that are interchangeably referred to as a base station (BS) or evolved or enhanced Node B (eNB) or access point (AP) at the system level herein. In this downlink case, the transceiver 14 above may be interchangeably referred to as a mobile station (MS) or user equipment (UE) or station (STA) at the system level herein. Further, the terms BS, eNB, and AP may be conceptually interchanged, depending on which wireless protocol is being used, so a reference to BS herein may also be seen as a reference to either of eNB or AP. Similarly, a reference to MS herein may also be seen as a reference to either of UE or STA.

When the user equipment transmits the last packet in its uplink buffer 20, it tells the evolved or enhanced node B (eNB) that it intends to disconnect from the network. The user equipment may also specify a time limit. The time limit specifies the first time after which an eNB grant, for network access for transmission or reception, may be received. The time limit creates a forced minimum delay for the next grant (FMD-NG). The time limit parameter allows the user equipment to wait an appropriate amount of time before confirming that it should expect no more packets to its uplink buffer.

The time limit parameter can be different for different applications on the user equipment. Selection of this parameter can be a client differentiator that allows client vendors to optimize the tradeoff between battery power consumption and latency. Also, this time limit should be less than the eNB dormancy timer (i.e. RRC Inactivity Timer) that forces the user equipment into the idle mode. The dormancy time forces the user equipment to idle mode after a specified period of inactivity measured by an absence of transmitted or received packets.

In one embodiment, a medium access control (MAC) control element (CE) may be used to implement this sequence. The medium access control control element is a faster-transition-to-idle (FTI) medium access control control element having a header field of the form R/R/E/LCID and a control element of length one octet. A new value for the logical channel identifier for uplink shared channel can be assigned for the new FTI medium access control control element. One of the reserved logical channel identifiers (LCIDs) for the uplink shared channel may be used for this purpose.

A faster-transition-to-idle medium access control control element (FIG. 3) may be 8 bits, including a faster-transition-to-idle mode bit, indicating an intention to go to idle mode when the FTI bit is equal to one. When the FTI bit is equal to one, the eNB may ignore the other bits. An FTI bit equal to zero indicates a user equipment's intention to get the next grant no earlier than the period indicated by a forced minimum delay for next grant (FMD-NG) bits. There may be three R bits that are “reserved” for future use. The FMD-NG bits indicate that the user equipment wants to get the next uplink grant no earlier than the time period specified by those bits. In one embodiment, 16 values possible with four bits are available that may be mapped to an index 0 to 15. For example, 0000 can be a forced minimum time for next grant of 20 milliseconds, while 1111 may be 500 milliseconds.

Then, the user equipment receives the grant after the time limit from the eNB. Next, the user equipment sends its confirmation on disconnecting from the network if there is no packet coming into its uplink buffer, or there is no indication to receive packets in the downlink buffer. The user equipment can send a confirmation on disconnecting from the network by using the FTI medium access control control element with FTI bit set equal to one.

In case there is a packet that has arrived in its uplink buffer, the user equipment transmits the packet. If this is the last packet in the buffer, then the disconnection can continue.

If there is any indication of receiving packets in the downlink buffer, the user equipment terminates the disconnection process.

When there is no activity in the uplink or downlink buffers for a period of time, the user equipment can initiate disconnection using the radio resource control (RRC) signaling based on the medium access control control element based mechanism as usual. That can be different from the sequence described above for user equipment initiated disconnecting at the end of an uplink data transmission.

Thus, a three way or step handshake is used, including (1) a request to transition to idle from the user equipment, (2) a granting of the request by an eNB, and (3) a confirmation by the user equipment.

The idle transition sequence 30, shown in FIG. 2, may be implemented in software, firmware and/or hardware. In software and firmware embodiments, it may be implemented by computer executed instructions stored in one or more non-transitory computer readable media, such as a magnetic, optical, or semiconductor storage.

The sequence 30 may begin by determining if the last packet has been transmitted from its uplink buffer, as determined in diamond 32. If not, the sequence waits for the last packet.

If it is the last packet, a disconnect notification is sent, as indicated in block 34. A disconnect notification includes the forced minimum delay for next grant, as indicated in block 36. Then, at block 38, the next grant is received after the expiration of the forced minimum delay for next grant time limit. If there is no packet in the uplink buffer, as indicated in diamond 40, and there is no indication to receive packets in the downlink buffer, as indicated in block 44, then the disconnection can be confirmed (block 48) using the faster-transition-to-idle medium access control control element with the FTI bit set to one.

However, if there is a packet in the uplink buffer, it may be transmitted, as indicated in block 42, and the flow returns to block 40 to check that no more packets are in the uplink buffer.

If there is an indication to receive packets in the downlink buffer, then the disconnection is terminated, as indicated in block 46, and the flow returns back to diamond 32.

The following clauses and/or examples pertain to further embodiments:

One example embodiment may be a method comprising sending a notification from user equipment of an intent to transition to idle mode, specifying a forced minimum delay for next grant, receiving a grant, checking whether a packet is in uplink or downlink buffers, and if no packets are in the buffers, confirming a transition to idle. The method may also include using a medium access control control element to specify said forced minimum delay for next grant. The method may also include using a logical channel identifier for an uplink shared channel in said element. The method may also include using a bit to signal a transition to idle. The method may also include using bits to signal a selectable delay time. The method may also include if a packet has arrived in the uplink buffer, transmitting the packet before transitioning to idle. The method may also include if there is an indication to receive packets in the downlink buffer, discarding the transition to idle. A method may also include specifying a forced minimum delay for next grant to indicate when another grant of network access is requested. A method may also include specifying a forced minimum delay for next grant that is shorter than an evolved node B dormancy timer. A method may also include requesting an immediate transition to idle mode.

In another example embodiment one or more non-transitory computer readable media storing instructions to cause a processor in a wireless device to perform a sequence comprising sending a notification from user equipment of an intent to transition to idle mode, specifying a forced minimum delay for next grant, receiving a grant, checking whether a packet is in uplink or downlink buffers, and if no packets are in the buffers, confirming a transition to idle. The media may further store instructions to perform a sequence including using a medium access control control element to specify said forced minimum delay for next grant. The media may further store instructions to perform a sequence including using a logical channel identifier for an uplink shared channel in said element. The media may further store instructions to perform a sequence including using a bit to signal a transition to idle. The media may further store instructions to perform a sequence including using bits to signal a selectable delay time. The media may further store instructions to perform a sequence including if a packet has arrived in the uplink buffer, transmitting the packet before transitioning to idle. The media may further store instructions to perform a sequence including if there is an indication to receive packets in the downlink buffer, discarding the transition to idle. The media may further store instructions to perform a sequence including specifying a forced minimum delay for next grant to indicate when another grant of network access is requested. The media may further store instructions to perform a sequence including specifying a forced minimum delay for next grant that is shorter than an evolved node B dormancy timer. The media may further store instructions to perform a sequence including requesting an immediate transition to idle mode.

Another example embodiment may be an apparatus comprising a transceiver to send a notification of an intent to transition to idle mode and to receive a grant, and a processor coupled to said transceiver to specify a forced minimum delay for next grant, check for a packet in uplink or downlink buffers, and if no packets are in the buffers, confirm a transition to idle. The apparatus may include said transceiver to use a medium access control control element to specify said forced minimum delay for next grant. The apparatus may include said transceiver to use a logical channel identifier for an uplink shared channel in said element. The apparatus may include said transceiver to use a bit to signal a transition to idle. The apparatus may include said transceiver to use bits to signal a selectable delay time. The apparatus may include if a packet has arrived in the uplink buffer, said transceiver to transmit the packet before transitioning to idle. The apparatus may include if there is an indication to receive packets in the downlink buffer, said processor to discard the transition to idle. The apparatus may include said processor to specify a forced minimum delay for next grant to indicate when another grant of network access is requested. The apparatus may include said processor to specify a forced minimum delay for next grant that is shorter than an evolved node B dormancy timer. The apparatus may include said processor to request an immediate transition to idle mode.

References throughout this specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation encompassed within the present invention. Thus, appearances of the phrase “one embodiment” or “in an embodiment” are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be instituted in other suitable forms other than the particular embodiment illustrated and all such forms may be encompassed within the claims of the present application.

While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

Claims

1. A method comprising:

sending a notification from user equipment of an intent to transition to idle mode;

specifying a forced minimum delay for next grant;

receiving a grant;

checking whether a packet is in uplink or downlink buffers; and

if no packets are in the buffers, confirming a transition to idle.

2. The method of claim 1 including using a medium access control control element to specify said forced minimum delay for next grant.

3. The method of claim 1 including using a logical channel identifier for an uplink shared channel in said element.

4. The method of claim 3 including using a bit to signal a transition to idle.

5. The method of claim 3 including using bits to signal a selectable delay time.

6. The method of claim 1 including if a packet has arrived in the uplink buffer, transmitting the packet before transitioning to idle.

7. The method of claim 6 including, if there is an indication to receive packets in the downlink buffer, discarding the transition to idle.

8. The method of claim 1 including specifying a forced minimum delay for next grant to indicate when another grant of network access is requested.

9. The method of claim 1 including specifying a forced minimum delay for next grant that is shorter than an evolved node B RRC Inactivity Timer.

10. The method of claim 1 including requesting an immediate transition to idle mode.

11. One or more non-transitory computer readable media storing instructions to cause a processor in a wireless device to perform a sequence comprising:

sending a notification from user equipment of an intent to transition to idle mode;

specifying a forced minimum delay for next grant;

receiving a grant;

checking whether a packet is in uplink or downlink buffers; and

if no packets are in the buffers, confirming a transition to idle.

12. The media of claim 11 further storing instructions to perform a sequence including using a medium access control control element to specify said forced minimum delay for next grant.

13. The media of claim 11 further storing instructions to perform a sequence including using a logical channel identifier for an uplink shared channel in said element.

14. The media of claim 11 further storing instructions to perform a sequence including using a bit to signal a transition to idle.

15. The media of claim 14 further storing instructions to perform a sequence including using bits to signal a selectable delay time.

16. The media of claim 11 further storing instructions to perform a sequence including if a packet has arrived in the uplink buffer, transmitting the packet before transitioning to idle.

17. The media of claim 16 further storing instructions to perform a sequence including if there is an indication to receive packets in the downlink buffer, discarding the transition to idle.

18. The media of claim 11 further storing instructions to perform a sequence including specifying a forced minimum delay for next grant to indicate when another grant of network access is requested.

19. The media of claim 11 further storing instructions to perform a sequence including specifying a forced minimum delay for next grant that is shorter than an evolved node B dormancy timer.

20. The media of claim 19 further storing instructions to perform a sequence including requesting an immediate transition to idle mode.

21. An apparatus comprising:

a transceiver to send a notification of an intent to transition to idle mode and to receive a grant; and

a processor coupled to said transceiver to specify a forced minimum delay for next grant, check for a packet in uplink or downlink buffers, and if no packets are in the buffers, confirm a transition to idle.

22. The apparatus of claim 21, said transceiver to use a medium access control control element to specify said forced minimum delay for next grant.

23. The apparatus of claim 21, said transceiver to use a logical channel identifier for an uplink shared channel in said element.

24. The apparatus of claim 23, said transceiver to use a bit to signal a transition to idle.

25. The apparatus of claim 23, said transceiver to use bits to signal a selectable delay time.

26. The apparatus of claim 21, including, if a packet has arrived in the uplink buffer, said transceiver to transmit the packet before transitioning to idle.

27. The apparatus of claim 26, including, if there is an indication to receive packets in the downlink buffer, said processor to discard the transition to idle.

28. The apparatus of claim 21, including, said processor to specify a forced minimum delay for next grant to indicate when another grant of network access is requested.

29. The apparatus of claim 21, including, said processor to specify a forced minimum delay for next grant that is shorter than an evolved node B dormancy timer.

30. The apparatus of claim 21, including, said processor to request an immediate transition to idle mode.