Overload control and supervision for wireless devices

Methods, systems, and/or devices are described for are provided for transmission overload control and/or supervision of wireless devices. Tools and techniques may be provided for resolving issues associated with numerous wireless devices connected to a base station. For example, a transmission cycle for an uplink channel may be identified where the transmission cycle is discontinuous. Scheduling request and or Random Access Channel messages may be transmitted from a wireless device based on the discontinuous transmission cycle. Tools and techniques are also provided that may involve supervision of numerous wireless devices. Supervision may, for example, involve keep-alive messages transmitted in accordance with a timer. The supervision may be based on determination of, and transmissions related to, a list or lists of connected wireless devices. In some cases, the wireless devices may be delay tolerant. The wireless devices may include UEs that may have long sleep cycles and/or machine-type communications (MTC) devices.

BACKGROUND

Different types of wireless devices may provide for automated communication. Automated wireless devices may include those implementing Machine-to-Machine (M2M) communication or Machine Type Communication (MTC). M2M and/or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station without human intervention. For example, M2M and/or MTC may refer to communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. These devices may be called M2M devices, MTC devices and/or MTC user equipments (UEs).

MTC devices may be used to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. The market for MTC devices is expected to grow rapidly as industries such as automotive, security, healthcare, and fleet management employ MTC to increase productivity, manage costs, and/or expand customer services. For example, it is estimated that the MTC connectivity market may grow to over 200 million devices employed in the field by 2014.

MTC devices may use a variety of wired and/or wireless communication technologies. For example, MTC devices may communicate with a network over various wireless cellular technologies such as 3GPP Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or various wireless networking technologies (e.g., IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), etc.). MTC devices may also communicate with one another using various peer-to-peer technologies such as Bluetooth, ZigBee, and/or other ad-hoc or mesh network technologies. The expansion of multiple access wireless networks around the world has made it far easier for MTC communication to take place and has lessened the amount of power and time necessary for information to be communicated between machines. These networks also allow an array of new business opportunities and connections between consumers and producers in terms of the products being sold.

The increasing number and reliance on MTC devices may create issues associated with scheduling transmissions, allocating resources, and managing context data associated with the MTC devices. Similar issues may also arise with user equipment (UEs) having long sleep cycles and/or other devices that may be capable of operating for extended time periods without transmitting or receiving a signal from another device or a base station.

SUMMARY

The described features generally relate to one or more improved systems, methods, and/or devices for transmission overload control and/or supervision of wireless devices. The systems, methods, and/or devices may include tools and techniques for resolving issues associated with numerous wireless devices connected to a base station.

Some embodiments include methods for overload control for one or more wireless devices in a connected state in a wireless communications system. In some embodiments, the methods may include identifying a first transmission cycle for an uplink channel. The methods may further include identifying a first off cycle with respect to the first transmission cycle for the uplink channel. The wireless device may refrain from transmitting during the first off cycle. Transmissions may occur according to the identified first transmission cycle. The transmissions may include, for example, a scheduling request or a random access channel message transmitted from a wireless device.

In some methods, the wireless device may be a delay-tolerant device. Delay tolerance may be defined with respect to a threshold. For example, a delay-tolerant device may be a device that is capable of operating for extended periods of time without communicating with another device and/or a base station. In some embodiments, delay tolerance is linked to a transmission cycle. In some aspects, the wireless device may be a UE with a long sleep cycle and/or an MTC device.

In some embodiments, the methods may include overload control for wireless devices that are part of a first set of wireless devices, which may utilize the first transmission cycle. Some other wireless devices may be part of a second set of wireless devices, which may utilize a second transmission cycle. The second transmission cycle may be staggered from the first cycle.

In some methods, the first transmission cycle may include staggered periods during which one or more components of a wireless device is powered on. In some embodiments, a discontinuous transmission (DTX) cycle includes the first transmission cycle and the first off cycle. The DTX cycle may utilize one or more timers for powering on and/or monitoring one or more components of the wireless devices. In some embodiments, the methods may include receiving an indication of the DTX cycle from a base station, and transmitting according to the received DTX cycle indication. In some embodiments, the methods may further include utilizing a discontinuous reception (DRX) cycle mask comprising DRX ON durations and DRX OFF durations, wherein the wireless device refrains from receiving during the DRX OFF durations.

In some methods, the first transmission cycle may correspond to a discontinuous reception (DRX) cycle. Some DRX ON durations of the DRX cycle may coincide with a DTX ON duration of the DTX cycle. In such cases, the DTX cycle may have a shorter period than the DRX cycle. In some embodiments, some DTX ON durations of the DTX cycle coincide with a DRX ON duration of the DRX cycle. In such cases, the DRX cycle may have a shorter period than the DTX cycle. In some embodiments, the features include a DRX cycle mask, which may provide that a wireless device is not required to receive during DRX OFF periods.

In some methods, the connected wireless device is in an RRC_CONNECTED state. The wireless device may be an ultra-low power device. In some embodiments, the methods may include receiving the first transmission cycle from a base station, such as an eNodeB (eNB). In some embodiments, the methods include a wireless device remaining in an RRC_CONNECTED state while in a sleep mode. The wireless device may operate according to the first transmission cycle received from the base station.

Some embodiments include systems for overload control for one or more wireless devices in a connected state in a wireless communications system. The systems may include means for identifying a first transmission cycle for an uplink channel. The system may further include means for identifying a first off cycle with respect to the first transmission cycle for an uplink channel. The wireless device may refrain from transmitting during the first off cycle. The systems may also include means for transmitting, which may occur according to the identified first transmission cycle. The transmissions may include, for example, at least a scheduling request or a random access channel message transmitted from a wireless device.

In some systems, the wireless device may be a delay-tolerant device. Delay tolerance may be defined with respect to a threshold. For example, a delay-tolerant device may be a device that is capable of operating for extended periods of time without communicating with another device and/or a base station. In some embodiments, delay tolerance may be linked to a transmission cycle. In some aspects, the wireless device may be a UE with a long sleep cycle and/or an MTC device.

In some systems, the wireless device may be part of a first set of wireless devices with means for utilizing the first transmission cycle. Some other wireless devices may be part of a second set of wireless devices with means for utilizing a second transmission cycle. The second transmission cycle may be staggered from the first cycle.

In some systems, the first transmission cycle may include staggered periods during which one or more components of a wireless device is powered on. In some embodiments, a discontinuous transmission (DTX) cycle includes the first transmission cycle and the first off cycle. The systems may further comprise means for the DTX cycle to utilize one or more timers for powering on and/or monitoring one or more components of the wireless devices. In some embodiments, the systems further comprise means for receiving an indication of the DTX cycle from a base station, and means for transmitting according to the received DTX cycle indication. In some embodiments, the systems further comprise means for utilizing a discontinuous reception (DRX) cycle mask, which includes DRX ON durations and DRX OFF durations, wherein the wireless device refrains from receiving during the DRX OFF durations.

In some systems, the first transmission cycle corresponds to a discontinuous reception (DRX) cycle. Some DRX ON durations of the DRX cycle may coincide with some DTX ON durations of the DTX cycle. In such cases, the DTX cycle may have a shorter period than the DRX cycle. In some embodiments, some DTX ON durations of the DTX cycle coincide with some DRX ON durations of the DRX cycle. In such cases, the DRX cycle may have a shorter period than the DTX cycle.

In some systems, the connected wireless device is in an RRC_CONNECTED state. The wireless device may be an ultra-low power device. In some aspects, the system may include means for receiving the first transmission cycle from a base station, such as an eNB. In some embodiments, the systems may include means for the wireless device remaining in an RRC_CONNECTED state while in a sleep mode. Some aspects may include means for operating the wireless device according to the first transmission cycle received from the base station.

Some embodiments include devices for overload control for one or more wireless devices in a connected state in a wireless communications system. In some embodiments, the devices include at least one processor with a memory coupled to the processor. The processor may be configured to identify a first transmission cycle for an uplink channel. In some embodiments, the processor may be configured to identify a first off cycle with respect to the first transmission cycle for the uplink channel. The wireless device refrain from transmitting during the first off cycle. In some embodiments, the processor is configured to transmit at least a scheduling request or a random access channel message according to the identified first transmission cycle from the wireless device.

In some embodiments, the wireless device may be part of a first set of wireless devices utilizing the first transmission cycle. Some other wireless devices may be part of a second set of wireless devices utilizing a second transmission cycle. The second transmission cycle may be staggered from the first cycle.

In some embodiments, the wireless device may be a delay-tolerant device. Delay tolerance may be defined with respect to a threshold. For example, a delay-tolerant device may be a device that is capable of operating for extended periods of time without communicating with another device and/or a base station. In some embodiments, delay tolerance may be linked to a transmission cycle. In some embodiments, the wireless device may be a UE with a long sleep cycle and/or an MTC device.

In some embodiments, the first transmission cycle may include staggered periods during which one or more components of a wireless device is powered on. In some embodiments, a discontinuous transmission (DTX) cycle comprises the first transmission cycle and the first off cycle. The processor may be further configured for the DTX cycle to utilize one or more timers for powering on and/or monitoring one or more components of the wireless devices. In some embodiments, the processor may be configured further to receive an indication of the DTX cycle from a base station, and to transmit according to the received DTX cycle indication. In some embodiments, the processor may be configured to utilize a discontinuous reception (DRX) cycle mask comprising DRX ON durations and DRX OFF durations, wherein the wireless device refrains from receiving during the DRX OFF durations.

In some embodiments, the first transmission cycle corresponds to a discontinuous reception (DRX) cycle. Some DRX ON durations of the DRX cycle may coincide with some DTX ON durations of the DTX cycle. In such cases, the DTX cycle may have a shorter period than the DRX cycle. In some embodiments, some DTX ON durations of the DTX cycle coincide with some DRX ON durations of the DRX cycle. In such cases, the DRX cycle may have a shorter period than the DTX cycle.

In some embodiments, the connected wireless device is in an RRC_CONNECTED state. The wireless device may be an ultra-low power device. In some embodiments, the processor may be configured to receive the first transmission cycle from a base station, such as an eNB. In some embodiments, the wireless device may include a processor configured for the wireless device remaining in an RRC_CONNECTED state while in a sleep mode. Some embodiments may include instructions executable by the processor to operate the wireless device according to the first transmission cycle received from the base station.

Some embodiments include computer program products for overload control for one or more wireless devices in a connected state in a wireless communications system. In some embodiments, the computer program products may include a non-transitory computer readable medium having program code recorded on it. The program code may include instructions for identifying a first transmission cycle for an uplink channel. The program code may include instructions for identifying a first off cycle with respect to the first transmission cycle for the uplink channel. The wireless device may refrain from transmitting during the first off cycle. In some embodiments, the program code may include instructions for transmitting at least a scheduling request or a random access channel message according to the identified first transmission cycle from the wireless device.

Some embodiments include methods for supervision of wireless devices in a wireless communications system. The methods may include initiating a timer at a wireless device after a handshake between the wireless device and a base station, such as an eNB. The wireless device may transmit a keep-alive handshake initiation message to the base station upon expiration of the timer. The handshake may include transmitting a first message and receiving a first response, which corresponds to the first message. Additionally or alternatively, the handshake may include receiving a second message and transmitting a second response, which corresponds to the second message.

In some embodiments of the method, the wireless device may be a delay-tolerant device. Delay tolerance may be defined with respect to a threshold. For example, a delay-tolerant device may be a device that is capable of operating for extended periods of time without communicating with another device and/or a base station. In some embodiments, delay tolerance may be linked to a transmission cycle. The wireless device may be a UE with a long sleep cycle and/or an MTC device.

The keep-alive handshake initiation message may be a random access channel message. In some embodiments, the methods include listening to a response message and replying with a closing message. In some embodiments, the keep-alive handshake initiation message is a scheduling request. In some embodiments, the methods include listening to an uplink grant and replying in a payload with a closing message. The methods may further include resetting the timer after the handshake.

Some embodiments include systems for supervision of wireless devices in a wireless communications system. In some embodiments, the systems include means for initiating a timer at a wireless device after a handshake between the wireless device and an base station. The systems may further include means for transmitting a keep-alive handshake initiation message to the base station upon expiration of the timer.

The keep-alive handshake initiation message may include, for example, a random access channel message. The systems may further include means for listening to a response message and means for replying with a closing message. In some embodiments, the keep-alive handshake initiation message is a scheduling request. The systems may include means for listening to an uplink grant and replying in a payload with a closing message. The systems may further include means for retting the timer after the handshake.

Some embodiments include devices for supervision of wireless devices in a wireless communications system. In some embodiments, the devices include at least one processor and a memory coupled to the processor. The processor may be configured to initiate a timer at a wireless device after a handshake between the wireless device and a base station. The processor may also be configured to transmit a keep-alive handshake initiation message to the base station upon expiration of the timer.

Some embodiments include computer program products for supervision of wireless devices in a wireless communications system. In some examples, the computer program products include a non-transitory computer readable medium having program code recorded on it. The program code may include instructions for initiating a timer at a wireless device after a handshake between the wireless device and a base station. The program code may also include instructions for transmitting a keep-alive handshake initiation message to the base station upon expiration of the timer.

Some embodiments include methods for supervision of wireless devices in a wireless communications system. In some embodiments, the methods include determining a list of connected wireless devices and broadcasting one or more messages that include the list of connected wireless devices. The methods may further include receiving a message from a wireless device that the wireless device is not on the list of connected wireless devices. The list of connected devices may, for example, include one or more wireless devices that have not transmitted a keep-alive message within a time period. In some embodiments, the broadcasting one or more messages includes transmitting a plurality of messages based on a staggered DRX cycle. Some messages from the plurality of messages may include a subset of connected wireless devices form the list of connected wireless devices.

In some embodiments, the wireless device or devices are delay tolerant. Delay tolerance may be defined with respect to a threshold. In some examples, delay tolerance may be linked to the first transmission cycle. In some embodiments, the wireless device or devices include a UE with a long sleep cycle or an MTC device.

Some embodiments include systems for supervision of wireless devices in a wireless communications system. In some examples, the systems include means for determining a list of connected wireless devices and means for broadcasting one or more messages including the list of connected wireless devices. In some embodiments, the systems further include means for receiving a message from a wireless device that the wireless device is not on the list of connected devices. The list of connected devices may include one or more wireless devices that have not transmitted a keep-alive handshake initiation message within a time period.

In some embodiments, the means for broadcasting the one or more messages includes means for transmitting a plurality of messages bases on a staggered DRX cycle. Some messages from the plurality of messages may include a subset of connected wireless devices from the list of connected wireless devices.

Some embodiments include devices for supervision of wireless devices in a wireless communications system. In some embodiments, the devices include at least one processor and a memory coupled to the processor. The processor may be configured to determine a list of connected devices and broadcast one or more messages including the list of connected devices.

Some embodiments include computer program products for supervision of wireless devices in a wireless communications system. In some embodiments, the computer program product may include a non-transitory computer readable medium having program code recorded on it. The program code may include instructions for determining a list of connected devices and broadcasting one or more messages including the list of connected devices.

DETAILED DESCRIPTION

Methods, systems, and devices for transmission overload control and/or supervision of wireless devices are provided in accordance with various embodiments. The methods, systems, and device may provide for resolving issues associated with numerous wireless devices connected to a base station. For example, tools and techniques are described that may be used to address issues associated with numerous connected wireless devices attempting to simultaneously transmit on an uplink. Further, tools and techniques are provided that may be used to address issues associated with infrequent communication between wireless devices and a base station, for example.

In some cases, the wireless devices may be a delay-tolerant device. For example, a delay-tolerant device may be a device that is capable of operating for extended periods of time without communicating with another device and/or a base station. In some aspects, delay tolerance may be linked to a transmission cycle. In some embodiments, the wireless device is a UE with a long sleep cycle and/or an MTC device.

The methods, systems, and devices described may be used for transmission overload control and/or supervision of wireless devices that are in a connected state. A connected wireless device may be in RRC_CONNECTED state, for example. Situations may exist in which wireless devices are each kept in RRC_CONNECTED state throughout a session with a base station, even when the wireless devices are in a power-saving mode (“deep sleep”). An advantage to maintaining wireless devices in RRC_CONNECTED may be that there may be no need to establish connection every time the wireless device needs to “wake-up,” which it may need to do to transmit or receive a signal. This may, however, present issues for a network having to cope with a large number of RRC_CONNECTED wireless devices. For example, a base station, such as an eNB, may need to maintain MTC device context data that is orders of magnitude greater than what the eNB would otherwise be required to maintain. Further, an eNB may need to schedule resources and manage Random Access Channel (RACH) messages for a large number of wireless devices. An eNB may need to manage the mobility state of a connected wireless device.

In a traditional LTE context, a discontinuous reception (DRX) cycle may be defined for user equipments (UEs), including MTC devices, in RRC_CONNECTED state. DRX typically involves a configurable cycle in which a UE monitors downlink control signaling during a specified subframe (DRX ON) and then “sleeps” (e.g., switches off receiver circuitry) during the remaining subframes (DRX OFF). Sleeping during the DRX OFF period may allow a UE to save power. Even in DRX, a UE could send an uplink Scheduling Request (SR) or RACH message anytime. An eNB may be obligated to respond to such an SR or RACH message. In a situation in which numerous UEs are in an RRC_CONNECTED state, even if sleeping, there could be a significant number of UEs that an eNB potentially has to schedule.

One solution may be to maintain wireless devices in RRC_IDLE and then restrict RACH messages for some period of time during overload conditions. This solution could, however, result in potentially long DRX ON periods with associated power consumption.

In some embodiments, a solution may be to maintain low duty cycle wireless devices in a discontinuous transmission (DTX) cycle for SR and/or a RACH transmissions or in a DTX cycle for all uplink signals. This may provide one example of a transmission overload control scheme. This transmission cycle may be staggered such that an eNB may only schedule a limited number of RRC_CONNECTED devices at any time. With this solution, the Physical Uplink Shared Channel (PUSCH) may not need to be regulated. In some cases, load throttling may be used if contention-based PUSCH is introduced. A solution employing both DRX and discontinuous transmission or DTX may be characterized such that the DRX cycle is sparser than the transmission or DTX cycle; or it may be characterized with a DRX cycle denser than a transmission or DTX cycle. In some embodiments, a DRX ON duration of a DRX cycle may coincide with a DTX ON duration of a DTX cycle. A DTX cycle may, for example, have a shorter period than a DRX cycle. In some cases, a DRX cycle may have a shorter period than a DTX cycle.

A transmission overload control scheme may be implemented in a variety of ways. For example, aspects of an implementation may involve an explicit SR and/or RACH occasion configuration in which wireless devices have staggered times when SR and/or RACH transmission is allowed. Aspects of an implementation may involve DTX for all uplink traffics, controlled with timers, e.g., dtxONtime and dtxINACTIVITYtimer, and associated rules governing transmissions. Aspects of some implementations may involve adding SR and/or RACH transmission periods to a DRX OFF restriction.

Tools and techniques also may be provided with regard to supervision schemes that may be implemented in a variety of ways. An MTC device, e.g., a meter or a sensor, may be configured with uplink (UL) semi-persistent scheduling (SPS), and such a device may rarely receive downlink (DL) unicast transmission. It is therefore possible that an eNB may prune a wireless device from its RRC_CONNECTED list. This pruning could occur for a number of reasons, including load control, inactivity, and/or radio link failure (RLF). This pruning may be transparent to a wireless device. It is thus possible that a wireless device may be transmitting but an eNB is not listening. If wireless devices are not able to avoid pruning (e.g., with a keep-alive technique) there may be undesirable outcomes, including a large number of transmitted packets lost, long times during which wireless devices are out-of-service, and/or jammed transmissions resulting from an eNB inadvertently scheduling over a resource dedicated to a wireless device.

These undesirable outcomes may be avoided if a wireless device runs a timer and/or a packet counter, for example. Such a timer may be reset after each handshake between a wireless device and an eNB. A timer may be an aspect of a wireless device or an aspect of an application layer. When a timer expires, a wireless device may initiate a keep-alive unicast handshake One example of a handshake may include a wireless device transmitting a message and receiving a response from an eNB. Another example of a handshake may include a wireless device receiving a message from an eNB and transmitting a response. Aspects of a handshake may involve a wireless device transmitting a RACH message, listening to an eNB for a response message, and replying with a closing message. Aspects of a handshake may involve sending an SR, listening for a UL grant, and replying in payload with a closing message. Such a procedure may be used for supervision of wireless devices or for eNB side supervision.

Undesirable pruning could be avoided with periodic broadcast messages from an eNB. An eNB may transmit to all wireless devices on a CONNECTED list. MTC devices may transmit a response indicating whether they should be on a CONNECTED list. A CONNECTED list may be reduced to only those wireless devices that did not have a unicast handshake recently. In some cases, a CONNECTED list may be transmitted in multiple broadcast messages aligned with wireless device DRX ON periods, and the list may include only wireless devices in the DRX ON period. Another list may be broadcast to, and include wireless devices on a staggered DRX ON period. In such a scenario, each list may be substantially smaller than a full CONNECTED list. Such a solution may provide UL and DL unicast transmission savings.

Techniques described herein may be used for various wireless communications systems such as cellular wireless systems, Peer-to-Peer wireless communications, wireless local access networks (WLANs), ad hoc networks, satellite communications systems, and other systems. The terms “system” and “network” are often used interchangeably. These wireless communications systems may employ a variety of radio communication technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single-Carrier FDMA (SC-FDMA), and/or other radio technologies. Generally, wireless communications are conducted according to a standardized implementation of one or more radio communication technologies called a Radio Access Technology (RAT). A wireless communications system or network that implements a Radio Access Technology may be called a Radio Access Network (RAN).

Referring first toFIG. 1, a diagram illustrates an example of a wireless communications system100in accordance with various embodiments. The system100includes base stations (or cells)105, wireless devices115, and a core network130. The base stations105may communicate with the wireless devices115under the control of a base station controller120, which may be part of the core network130or the base stations105in various embodiments. Base stations105may communicate control information and/or user data with the core network130through backhaul links132. In some embodiments, the base stations105may communicate, either directly or indirectly, with each other over backhaul links134, which may be wired or wireless communication links. The system100may support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can transmit modulated signals simultaneously on the multiple carriers. For example, each communication link125may be a multi-carrier signal modulated according to the various radio technologies described above. Each modulated signal may be sent on a different carrier and may carry control information (e.g., reference signals, control channels, etc.), overhead information, data, etc.

The base stations105may wirelessly communicate with the wireless devices115via one or more base station antennas. Each of the base station105sites may provide communication coverage for a respective geographic area110. In some embodiments, base stations105may be referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a basic service set (BSS), an extended service set (ESS), a NodeB, eNodeB (eNB), Home NodeB, a Home eNodeB, or some other suitable terminology. The coverage area110for a base station may be divided into sectors making up only a portion of the coverage area (not shown). The system100may include base stations105of different types (e.g., macro, micro, pico, and/or femto base stations). There may be overlapping coverage areas for different technologies.

In some embodiments, the system100is an LTE/LTE-A network. In LTE/LTE-A networks, the terms evolved Node B or eNodeB (eNB) and user equipment (UE) may be generally used to describe the base stations105and wireless devices115, respectively. The system100may be a Heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographical regions. For example, each eNB105may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A pico cell would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a pico cell may be referred to as a pico eNB. And, an eNB for a femto cell may be referred to as a femto eNB or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells.

The core network130may communicate with the eNBs105via a backhaul132(e.g., S1, etc.). The eNBs105may also communicate with one another, e.g., directly or indirectly via backhaul links134(e.g., X2, etc.) and/or via backhaul links132(e.g., through core network130). The wireless network100may support synchronous or asynchronous operation. For synchronous operation, the eNBs may have similar frame timing, and transmissions from different eNBs may be approximately aligned in time. For asynchronous operation, the eNBs may have different frame timing, and transmissions from different eNBs may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

The wireless devices115are dispersed throughout the wireless network100, and each wireless device may be stationary or mobile. A wireless device115may also be referred to by those skilled in the art as a UE, mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A wireless device115may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, an MTC device, or the like. A wireless device may be able to communicate with macro eNBs, pico eNBs, femto eNBs, relays, and the like.

The transmission links125shown in network100may include uplink (UL) transmissions from a wireless device115to a base station105, and/or downlink (DL) transmissions, from a base station105to a mobile device115. The downlink transmissions may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions.

Some of the wireless devices115may be machine type communication (MTC) devices115that perform various functions, capture information, and/or communicate information with limited or no human intervention. For example, MTC devices115may include sensors and/or meters for monitoring and/or tracking other devices, environmental conditions, etc. MTC devices115may be standalone devices or, in embodiments, MTC devices115may be modules incorporated in other devices. For example, devices (e.g., user equipment, mobile stations, etc.) such as smart phones, cellular phones and wireless communications devices, personal digital assistants (PDAs), tablets, other handheld devices, netbooks, ultrabooks, smartbooks, notebook computers, surveillance cameras, handheld medical scanning devices, home appliances, etc. may include one or more MTC device modules115. In the ensuing description, various techniques are described as applied to communications and processing for a system including a network and one or more MTC devices. It should be understood that the described techniques may be advantageously applied to other devices such as those incorporating MTC devices and/or other wireless devices. For example, the wireless devices115may be UEs that may have long sleep cycles and/or MTC devices, including ultra-low power MTC devices. In some aspects, the wireless devices115may be or include delay-tolerant devices.

The information collected by the MTC wireless devices115may be transmitted across a network that includes components of system100to a back-end system, such as a server. The transmission of data to/from the MTC devices115may be routed through the base stations105. The base stations105may communicate with the MTC devices115on a forward link for transmitting signaling and/or information to the MTC devices115and on a reverse link for receiving signaling and/or information from the MTC devices115.

In one example, the network controller120may be coupled to a set of base stations and provide coordination and control for these base stations105. The controller120may communicate with the base stations105via a backhaul (e.g., core network130). The base stations105may also communicate with one another directly or indirectly and/or via wireless or wireline backhaul.

The different aspects of system100, such as the wireless devices115, the base stations105, the core network130, and/or the controller120may be configured for transmission overload control and/or supervision of different wireless devices115with deep sleep cycles, in RRC_CONNECTED state. In some cases, the wireless devices115may include ultra-low power MTC devices. For example, aspects of the wireless devices115may be configured for identifying a transmission cycle for an uplink channel. The transmission cycle may be discontinuous. The wireless devices115may transmit SR and/or RACH messages, and/or other signals or data, according to an identified transmission cycle. In some cases, one or more eNBs105may be configured to establish and broadcast, or otherwise send, one or more transmission cycles to the wireless devices115. Aspects of the system100may include supervision of the wireless devices115, which may include a wireless device115sending a keep-alive message to an eNB105at set intervals in order to avoid pruning. In some cases, an eNB105may be configured to broadcast a list of connected devices, to which the wireless devices115may respond in order to avoid pruning.

FIG. 2illustrates an example of a wireless communications system200implementing a machine type communication service over an LTE/LTE-Advanced network in accordance with various embodiments. The system200may be an example of aspects of system100. The system200may be implemented to maintain low duty cycle MTC devices in a discontinuous transmission cycle for SR and/or RACH or in a discontinuous transmission (DTX) cycle for all uplink signals. This transmission cycle may be staggered such that an eNB may only schedule a limited number of RRC_CONNECTED devices at any time. The system200may include a number of wireless devices115-aand115-b, and an eNB105-a. The eNB105-amay be an example of the base stations illustrated inFIG. 1. The wireless devices115-amay be examples of the wireless devices115illustrated inFIG. 1. The eNB105-amay determine and transmit210information regarding transmission cycles for the wireless devices115-aand115-b. The wireless devices115-aand115-bmay identify a transmission cycle for an uplink channel, and the wireless devices115-aand115-bmay identify an off cycle with respect to the transmission cycle. The transmission cycle for the wireless devices115-amay be different from the transmission cycle for the wireless devices115-b; and one or both cycles may be discontinuous. The wireless devices115-aand115-bmay transmit according to an identified transmission cycle, and the wireless devices115-aand115-bmay refrain from transmitting during the off cycle. One skilled in the art would understand that the quantity of wireless devices115-a, eNBs105-a, and communications210shown inFIG. 2is for illustration purposes only and should not be construed as limiting. The wireless devices115-amay be a delay-tolerant device. In some embodiments, the wireless devices115-amay include UEs with a long sleep cycle and/or MTC devices.

The wireless communications system200may be operable to facilitate machine type communication between one or more MTC devices115-aand/or one or more eNBs105-a. Machine type communication may include communications between one or more devices without human intervention. In one example, machine type communication may include the automated exchange of data between a remote machine, such as a wireless device115-a, and a back-end IT infrastructure without user intervention. The transfer of data from a wireless device115-ato a server, another wireless device115-b, or the eNB105-amay be performed using reverse link communications. Data collected by the wireless devices115-aor115-b(e.g., monitoring data, sensor data, meter data, etc.) may be transferred on the reverse link communications. The wireless devices115-aand115-bmay be on staggered transmission cycles such that the wireless devices115-atransmit according to one cycle, during which the wireless devices115-bmay not transmit. Likewise, the wireless devices115-bmay transmit according to a separate cycle, during which the wireless devices115-amay not transmit. In this way, each of the wireless devices115-aand115-bmay remain in RRC_CONNECTED state, but the eNB105-amay be able to effectively schedule resources and coordinate RACH processes because the number of MTC devices that may transmit at a given time may be limited.

The transfer of data to wireless device115-aor115-bvia the eNB105-amay be performed via forward link (e.g., downlink) communications. The forward link may be used to send instructions, software/firmware updates, and/or messages to the wireless devices115-aor115-b. The instructions may instruct the wireless devices115-aor115-bto remotely monitor equipment, environmental conditions, etc. Machine type communication (MTC) may be used with various applications such as, but not limited to, remote monitoring, measurement and condition recording, fleet management and asset tracking, in-field data collection, distribution, physical access control, and/or storage, etc. The eNB105-amay generate one or more forward link frames with a small number of channels to transmit instructions, software/firmware updates, and/or messages. The various wireless devices115-aand/or115-bmay operate according to a DRX cycle, and they may wake up (e.g., power on) to monitor a specific frame when instructions or other data is included on a channel of that frame. In some embodiments, aspects of the wireless devices115-aand/or115-bmay transmit according to a DRX cycle mask, which may allow the wireless devices115-aand/or115-bto refrain from receiving during DRX OFF periods.

In some embodiments, the behavior of the wireless devices115-aand/or115-bmay be pre-defined. For example, the day, time, etc. to monitor another device and transmit the collected information may be pre-defined for a wireless device115-a. In some embodiments, the wireless device115-a-1may be an MTC device and may be programmed to begin monitoring another device and collect information about that other device at a first pre-defined time period. The wireless device115-a-1may also be programmed to transmit the collected information at a second pre-defined time period. The determined transmission cycle may account for or may be based on a predefined monitoring time.

Turning next toFIGS. 3A, 3B, and 3C, block diagrams illustrate devices300-a,300-b, and/or300-cfor transmission overload control of a wireless device in accordance with various embodiments. The devices300-a,300-b, and/or300-cmay be examples of one or more aspects of base stations105and/or wireless devices115described with reference toFIGS. 1 and 2. The wireless devices115may be delay-tolerant devices, for example. In some embodiments, the wireless devices115may be UEs with a long sleep cycle and/or MTC devices. The devices300-a,300-b, and/or300-cmay also be processors. The device300-amay include a receiver module305, a transmission overload control module310, and/or a transmitter module315. The device300-bmay include a receiver module305, a transmission overload control module310-a, and/or a transmitter module315. The device300-cmay include a receiver module305, a transmission overload control module310-b, and/or a transmitter module315. Each of these components may be in communication with each other. Each of the components of each device may be in communication with other components of the device.

These components of the devices300-a,300-b, and/or300-cmay, individually or collectively, be implemented with one or more application-specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. Alternatively, the functions may be performed by one or more other processing units (or cores), on one or more integrated circuits. In other embodiments, other types of integrated circuits may be used (e.g., Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), and other Semi-Custom ICs), which may be programmed in any manner known in the art. The functions of each unit may also be implemented, in whole or in part, with instructions embodied in a memory or other non-transitory computer-readable medium, formatted to be executed by one or more general or application-specific processors.

The receiver module305inFIGS. 3A, 3B, and 3Cmay receive information such as packet, data, and/or signaling information, including information related to a transmission cycle, regarding what the device300-ahas received or transmitted. The received information may be utilized by the transmission overload control module310for a variety of purposes. For example, the received information may be utilized for transmission cycle determination by a wireless device115.

The receiver module305may be configured to receive a reverse link (e g, uplink) physical layer packet sent from a wireless device115using reverse link communications. The receiver module305may also be configured to receive instructions, transmission cycle information, a set of operations, messages, etc. from an eNB105.

The transmission overload control module310may determine a transmission cycle and initiate transmission during designated transmission periods. The transmission overload control modules310-aand310-bof devices300-band300-c, shown inFIGS. 3B and 3C, may be examples of aspects of transmission overload control module310. In some examples, modules310-aand310-binclude submodules of the transmission overload control module310. The transmission overload control module310-a, shown inFIG. 3B, may include a transmission cycle identification module311and the SR/RACH transmission module312. In some embodiments, the transmission cycle identification modules311may process and/or identify information from an eNB105regarding a designated transmission cycle, DTX, and/or DRX. In some embodiments, the SR/RACH transmission module312may initiate transmission of an SR, RACH message, and/or other uplink transmissions according to the identified transmission cycle or DTX. Additionally or alternatively, the SR/Transmission module312may cause the device300-bto refrain from transmitting an SR and/or RACH message. The transmission overload control module310-b, shown inFIG. 3C, may include the transmission cycle determination module313and the transmission cycle transmission module314. In some embodiments, the transmission cycle determination module313may determine and/or establish a transmission cycle and/or an off cycle for one or more wireless devices115. In some embodiments, the transmission cycle transmission module314may initiate or facilitate communicating the determined transmission cycle and/or off cycle to one or more wireless devices115.

In some embodiments, the transmitter module315may transmit an SR, RACH message, and/or other uplink transmissions according to an identified transmission cycle. In some embodiments, the transmitter module315may transmit downlink transmissions, including, for example, a transmission cycle to one or more wireless devices115.

FIGS. 4A and 4Billustrate examples of systems400-aand400-bimplementing machine type communication supervision procedures in accordance with various embodiments. The systems400-aand400-bmay be examples of aspects of the system100inFIG. 1. Possible issues associated with infrequent communication between a wireless device and an eNB may potentially be avoided if a wireless device runs a timer. Such a timer may be reset after each handshake between a wireless device and an eNB. A timer may be an aspect of, for example, a wireless device115, which may be an MTC device. When a timer expires, a wireless device may initiate a keep-alive handshake Such a procedure may be used for supervision of wireless devices or for eNB side supervision. The system400-amay include a wireless device115-c-1and an eNB105-b-1. The eNB105-b-1may be an example of the base stations illustrated inFIG. 1. The wireless devices115-c-1may be examples of the wireless devices115illustrated inFIG. 1. A timer may be initiated at the wireless device115-c-1after a handshake between the wireless device115-c-1and the eNB105-b-1. A timer may be initiated by the wireless device115-c-1. The wireless device115-c-1may transmit a keep-alive handshake initiation message410to the eNB105-b-1upon expiration of a timer. The keep-alive handshake initiation message410may be a RACH message. Alternatively, the keep-alive handshake initiation message410may include an SR. In response to the keep-alive handshake initiation message410, the eNB105-b-1may transmit a response415. A response415may be a RACH message or an UL grant. The wireless device115-c-1may transmit a reply420. A reply420may be a closing message. A reply420may include a RACH message or a payload with a closing message. In some embodiments, the wireless devices115-c-1may be UEs that may have long sleep cycles and/or MTC devices, including ultra-low power MTC devices. In some cases, the wireless devices115-c-1may involve delay-tolerant devices.

The system400-bmay include an MTC device115-c-2and an eNB105-b-2. The eNB105-b-2may be an example of the base station105-b-1illustrated inFIG. 4A. The MTC device115-c-2may be an example of a wireless device115-c-1illustrated inFIG. 4A. The MTC device115-c-2may initiate a timer. When the timer expires405, the MTC device115-c-2may transmit a keep-alive handshake initiation message410-a. In response, the eNB105-b-2may transmit a response message415-a. In reply, the MTC device115-c-2may transmit a closing message420-a. Although discussed in terms of an MTC device, device115-c-2may, in some embodiments, be a UE that having a long sleep cycle. Device115-c-2may be an ultra-low power MTC. In some aspects, device115-c-2may include delay-tolerant features such that it may be capable of operating for extended time periods without transmitting or receiving a signal.

FIGS. 5A and 5Billustrate examples of wireless communication systems500-aand500-bimplementing wireless device supervision procedures in accordance with various embodiments. The systems500-aand500-bmay be examples of aspects of the system100inFIG. 1. An eNB may transmit to all wireless devices on a CONNECTED list to, for example, ascertain which devices may be actually connected and which may be candidates for pruning. Wireless devices may transmit a response indicating whether they should be on a CONNECTED list. The system500-amay include wireless devices115-dand115-eand an eNB105-c-1. The eNB105-c-1may be an example of the base stations illustrated inFIG. 1. The wireless devices115-dand115-emay be examples of the wireless devices115illustrated inFIG. 1. The eNB105-c-1may determine a list of connected devices, which may include wireless devices115-dand/or115-e. The eNB105-c-1may broadcast510one or more messages that include or corresponds to a list of connected devices. The wireless devices115-dand/or115-emay receive a broadcast510including a list of connected devices. The wireless devices115-dand/or115-emay determine whether they are on the list of connected devices. Whether the wireless devices115-dand/or115-eare on the list of connected devices may be a function of whether the wireless devices115-dand/or115-ehave transmitted a keep-alive handshake initiation message or engaged in a handshake with the eNB105-c-1within a designated time period. The wireless devices115-dand/or115-emay transmit a message520indicating that the wireless devices115-dand/or115-eare not on the list of connected devices, but that the wireless devices115-dand115-eare connected to the eNB105-c-1and should be on the list. The eNB105-c-1may receive the message520from the wireless devices115-dand/or115-ethat those devices are not, but should be, on a list of connected devices. In some embodiments, the wireless devices115-dand/or115-emay be UEs that may have long sleep cycles. In some embodiments, the wireless devices115-dand/or115-emay be MTC devices, including ultra-low power MTC devices. In some cases, the wireless devices115-dand/or115-emay be or involve delay-tolerant devices.

The system500-bmay include an MTC device115-e-3and an eNB105-c-2. The eNB105-c-2may be an example of the base station105-c-1illustrated inFIG. 5A. The MTC device115-e-3may be an example of a wireless device115illustrated inFIG. 5A, which is connected to the eNB105-c-2. The eNB105-c-2may determine505a list of connected devices. The eNB105-c-2may broadcast510-aa list of connected devices. A broadcast510-amay include transmitting more than one message based on a DRX cycle such that each message includes a subset of devices from the list of connected devices. The MTC device115-e-3may receive the broadcast510-aand/or determine512that it is not on the list of connected devices. The MTC device115-e-3may transmit a response message520-ato the eNB105-c-2that the MTC device115-e-3should be on the list of connected devices. Although discussed in terms of an MTC device, device115-e-3may, in some embodiments, be a UE that may have a long sleep cycle. Device115-e-3may be an ultra-low power MTC. In some aspects, device115-e-3may include delay-tolerant features such that it may be capable of operating for extended time periods without transmitting or receiving a signal.

Turning next toFIGS. 6A, 6B, and 6C, block diagrams illustrate devices600-a,600-b, and/or600-cfor supervision of a wireless device in accordance with various embodiments. The devices600-a,600-b, and/or600-cmay be examples of one or more aspects of base stations105and/or wireless devices115described with reference toFIGS. 1, 2, 4A, 4B, 5A, and 5B. The devices600-a,600-b, and/or600-cmay also be processors. The device600-amay include a receiver module605, a supervision module610, and/or a transmitter module615. The device600-bmay include a receiver module605, a supervision module610-a, and or a transmitter module615. The device600-cmay include a receiver module605, a supervision module610-b, and/or transmitter module615. Each of the components of each device may be in communication with other components of the device.

These components of the devices600-a,600-b, and/or600-cmay, individually or collectively, be implemented with one or more application-specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. Alternatively, the functions may be performed by one or more other processing units (or cores), on one or more integrated circuits. In other embodiments, other types of integrated circuits may be used (e.g., Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), and other Semi-Custom ICs), which may be programmed in any manner known in the art. The functions of each unit may also be implemented, in whole or in part, with instructions embodied in a memory or other non-transitory computer-readable medium, formatted to be executed by one or more general or application-specific processors.

The receiver module605inFIGS. 6A, 6B, and/or6C may receive information such as packet, data, and/or signaling information, including information related to a transmission cycle, regarding what the device600-ahas received or transmitted. The received information may be utilized by the supervision module610for a variety of purposes. For example, the received information may be utilized for transmission cycle determination by an eNB105.

The receiver module605may be configured to receive a reverse link (e.g., uplink) physical layer packet sent from a wireless device115using reverse link communications. The receiver module605may also be configured to receive instructions, transmission cycle information, a set of operations, messages, etc. from a wireless device115or an eNB105.

The supervision module610may initiate a timer and/or a keep-alive message. The supervision module610may facilitate listening to, processing, and/or replying to messages from an eNB105. The supervision module610may determine a list of connected devices and initiate a broadcast transmission. The supervision module610may facilitate pruning of wireless devices115from a list of connected devices. The supervision module610may facilitate listening to, processing, and/or replying to messages from an MTC device115. The supervision modules610-aand610-bof devices600-band600-c, shown respectively inFIGS. 6B and 6C, may be examples of aspects of the supervision module610. In some examples, modules610-aand610-binclude submodules of the supervision module610.

The transmitter module615may transmit an SR, RACH message, and/or other uplink and or downlink transmission according to an identified and/or determined transmission, DTX, and/or DRX cycle.

FIG. 7shows a block diagram of a communications system700that may be configured for transmission overload control and/or supervision of wireless devices115. This system700may be an example of aspects of the system100depicted inFIG. 1, system200ofFIG. 2, device300-aofFIG. 3A, system400-aofFIG. 4A, system500-aofFIG. 5A, and or device600-aofFIG. 6A. System700may include a base station105-d. The base station105-dmay include antenna(s)745, a transceiver module750, memory780, and a processor module770, which each may be in communication, directly or indirectly, with each other (e.g., over one or more buses). The transceiver module750may be configured to communicate bi-directionally, via the antenna(s)745, with a wireless device115-e. Alternatively or in addition, the transceiver module750may be configured to communicate with one or more UEs that may have a long sleep cycle. The transceiver module750may be configured to communicate with an MTC device, which may be an ultra-low power MTC device. In some aspects, the transceiver module750may be capable of communicating with delay-tolerant devices, which themselves may be capable of operating for extended time periods without transmitting or receiving a signal. The transceiver module750(and/or other components of the base station105-d) may also be configured to communicate bi-directionally with one or more networks. In some cases, the base station105-dmay communicate with the core network130-aand/or the controller120-athrough network communications module775. The base station105-dmay be an example of an eNodeB base station, a Home eNodeB base station, a NodeB base station, and/or a Home NodeB base station. Controller120-amay be integrated into base station105-din some cases, such as with an eNodeB base station.

Base station105-dmay also communicate with other base stations105, such as base station105-mand base station105-n. Each of the base stations105may communicate with the wireless device115-eusing different wireless communications technologies, such as different Radio Access Technologies. Base station105-dmay perform and/or facilitate transmission overload control of one or more wireless devices using transmission overload control module310-c. Base station105-dmay perform and/or facilitate supervision using supervision module610-c. Transmission overload control and supervision may include determining, identifying, transmitting, and receiving according to a transmission cycle, DTX, and/or DRX. In some cases, base station105-dmay communicate with other base stations such as105-mand/or105-nutilizing base station communication module765. In some embodiments, base station communication module765may provide an X2 interface within an LTE wireless communication technology to provide communication between some of the base stations105. In some embodiments, base station105-dmay communicate with other base stations through controller120-aand/or core network130-a.

The memory780may include random access memory (RAM) and read-only memory (ROM). The memory780may also store computer-readable, computer-executable software code785containing instructions that are configured to, when executed, cause the processor module770to perform various functions described herein (e.g., transmission overload control, supervision, keep-alive messaging, pruning, etc.). Alternatively, the software code785may not be directly executable by the processor module770but be configured to cause the computer, e.g., when compiled and executed, to perform functions described herein.

The processor module770may include an intelligent hardware device, e.g., a central processing unit (CPU) such as those made by Intel® Corporation or AMD®, a microcontroller, an application-specific integrated circuit (ASIC), etc. The processor module770may include a speech encoder (not shown) configured to receive audio via a microphone, convert the audio into packets (e.g., 30 ms in length, etc.) representative of the received audio, provide the audio packets to the transceiver module750, and provide indications of whether a user is speaking. Alternatively, an encoder may only provide packets to the transceiver module750, with the provision or withholding/suppression of the packet itself providing the indication of whether a user is speaking.

The transceiver module750may include a modem configured to modulate the packets and provide the modulated packets to the antenna(s)745for transmission, and to demodulate packets received from the antenna(s)745. While some examples of the base station105-dmay include a single antenna745, the base station105-dpreferably includes multiple antennas745for multiple links which may support carrier aggregation. For example, one or more links may be used to support macro communications with the wireless device115-e.

According to the architecture ofFIG. 7, the base station105-dmay further include a communications management module760. The communications management module760may manage communications with other base stations105-mor105-n. By way of example, the communications management module760may be a component of the base station105-din communication with some or all of the other components of the base station105-dvia a bus. Alternatively, functionality of the communications management module760may be implemented as a component of the transceiver module750, as a computer program product or aspects of a non-transitory computer-readable storage medium, and/or as one or more controller elements of the processor module770.

The components for base station105-dmay be configured to implement overload control and supervision techniques discussed above with respect to devices300-a,300-b,300-c,600-a,600-b, and/or600-c, ofFIGS. 3A, 3B, 3C, 6A, 6B, and/or6C, respectively, and may not be repeated here for the sake of brevity. For example, the transmission overload control module310-cmay include similar functionality as the transmission overload control module310,310-a, and/or310-bofFIGS. 3A, 3B, and 3C, respectively. As another example, the supervision module610-cmay include similar functionality as the supervision module610,610-a, and/or610-bofFIGS. 6A, 6B, and 6C, respectively.

In some embodiments, the transceiver module750in conjunction with antenna(s)745, along with other possible components of base station105-d, may receive or transmit information or messages corresponding to a transmission cycle. In some embodiments, the transceiver module750in conjunction with antenna(s)745, along with other possible components of base station105-d, may receive or transmit information or messages corresponding to the wireless device115-e, to other base stations105-m/105-n, or core network130-a, such as a list of connected devices.

FIG. 8is a block diagram800of a wireless device115-fconfigured for overload control and/or supervision in accordance with various embodiments. The wireless device115-fmay have any of various configurations, such as a sensor or monitor for various MTC applications discussed above. The wireless device115-fmay have an internal power supply (not shown), such as a small battery, to facilitate mobile operation. The wireless device115-fmay be an MTC device, including an ultra-low power MTC device. In some embodiments, the wireless device115-fmay be the wireless device115ofFIGS. 1, 2, 4A, 4B, 5A, and/or5B. The wireless device115-fmay include aspects of devices300-a,300-b,300-c,600-a,600-b, and/or600-cofFIGS. 3A, 3B, 3C, 6A, 6B and/or 6B. Although discussed in terms of an MTC device, device115-fmay, in some embodiments, be a UE that may have a long sleep cycle. Device115-fmay be an ultra-low power MTC. In some aspects, device115-fmay include delay-tolerant features such that it may be capable of operating for extended time periods without transmitting or receiving a signal.

The wireless device115-fmay include a transmission overload control module310-dand/or a supervision module610-d, a sensor815, antenna(s)845, a transceiver module850, memory880, and a processor module870, which each may be in communication, directly or indirectly, with each other (e.g., via one or more buses). The transceiver module850may be configured to communicate bi-directionally, via the antenna(s)845and/or one or more wired or wireless links, with one or more networks, as described above. For example, the transceiver module850may be configured to communicate bi-directionally with base stations105ofFIG. 1,FIGS. 2, 4A, and/or4B. The transceiver module850may include a modem configured to modulate packets and provide the modulated packets to the antenna(s)845for transmission, and to demodulate packets received from the antenna(s)845. While the wireless device115-fmay include a single antenna845, the wireless device115-fmay include multiple antennas845for multiple transmission links. In some cases, the sensor815may be an aspect of a meter or implement other monitoring functionality of the wireless device115-f. The input of the sensor815may be communicated to, e.g., a server (not shown) via the other components of the wireless device815and a base station.

The memory880may include random access memory (RAM) and read-only memory (ROM). The memory880may store computer-readable, computer-executable software code885containing instructions that are configured to, when executed, cause the processor module870to perform various functions described herein (e.g., transmission overload control, supervision, keep-alive messaging, etc.). Alternatively, the software code885may not be directly executable by the processor module870but be configured to cause the computer (e.g., when compiled and executed) to perform functions described herein.

The processor module870may include an intelligent hardware device, e.g., a central processing unit (CPU) such as those made by Intel® Corporation or AMD®, a microcontroller, an application-specific integrated circuit (ASIC), etc.

According to the architecture ofFIG. 8, the wireless device115-fmay further include a communications management module860. The communications management module860may manage communications with base stations105and/or other wireless devices115. By way of example, the communications management module860may be a component of the wireless device115-fin communication with some or all of the other components of the wireless device115-fvia a bus. Alternatively, functionality of the communications management module860may be implemented as a component of the transceiver module850, as a computer program product of a non-transitory computer readable medium, and/or as one or more controller elements of the processor module870.

The components for the wireless device115-fmay be configured to implement aspects discussed above with respect to devices300-a,300-b, or300-cofFIGS. 3A, 3B, and 3C, respectively, and may not be repeated here for the sake of brevity. For example, the transmission overload control module310-dmay include similar functionality as the module310ofFIG. 3A. Aspects of310-aand/or310-bofFIGS. 3B and 3C, respectively, may be examples of aspects of the transmission overload control module310-d.

In some embodiments, the transceiver module850in conjunction with antenna(s)845, along with other possible components of the wireless device115-f, may transmit information regarding SR and/or RACH messages from the wireless device115-fto base stations or a core network. In some embodiments, the transceiver module850, in conjunction with antennas845along with other possible components of the wireless device115-f, may transmit information, related to wireless device overload control and supervision, including transmission cycle, off cycle, DRX cycle, connected list status, to base stations or a core network such that these devices or systems may utilize flexible waveforms.

FIG. 9is a block diagram of a system900including a base station105-eand an MTC device115-gin accordance with various embodiments. This system900may be an example of aspects of the system100ofFIG. 1, system200ofFIG. 2, system400-aofFIG. 4, and/or system500-aofFIG. 5. The base station105-emay be equipped with antennas934-athrough934-x, and the wireless device115-gmay be equipped with antennas952-athrough952-n. At the base station105-e, a transmit processor920may receive data from a data source. For example, the base station105-emay communicate with one or more UEs that may have a long sleep cycle. In some embodiments, the base station105-emay communicate with an MTC device, which may be an ultra-low power MTC device. In some aspects, the base station105-emay be capable of communicating with delay-tolerant devices, which themselves may be capable of operating for extended time periods without transmitting or receiving a signal.

The transmitter processor920may process the data. The transmitter processor920may also generate reference symbols, and a cell-specific reference signal. A transmit (TX) MIMO processor930may perform spatial processing (e.g., precoding) on data symbols, control symbols, and/or reference symbols, if applicable, and may provide output symbol streams to the transmit modulators932-athrough932-x. Each modulator932may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator932may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink (DL) signal. In one example, DL signals from modulators932-athrough932-xmay be transmitted via the antennas934-athrough934-x, respectively. The transmitter processor920may receive information from a processor940. The processor940may be configured to communicate with a transmission overload control module310-eand a supervision module610-e, in accordance with the embodiments described above in conjunction with310,310-a,310-b,610,610-a, and610-binFIGS. 3A, 3B, 3C, 6A, 6B, and 6C. In some embodiments, the processor940may be implemented as part of a general processor, the transmitter processor920, and/or the receiver processor938. A memory942may be coupled with the processor940.

In some embodiments, the processor940is configured to determine and/or establish a transmission, off, DTX, and/or DRX cycle for MTC devices115. For example, processor940may be configured to establish a discontinuous transmission cycle for SR and RACH messages for the wireless device115-g, in conjunction with transmitter processor920and transmitter MIMO processor930, modulators932and antennas934. Processor940may further be configured to determine a list of connected wireless devices115, and process messages received in response to a broadcast of a list of connected devices, through MIMO detector936and processor938, de-modulators932, and antennas934.

The processor940may further be configured to determine a list of connected wireless devices115that have not transmitted a keep-alive message within a time period specified and/or determined by the processor940.

At the wireless device115-g, the mobile device antennas952-athrough952-nmay receive the DL signals from the base station105-eand may provide the received signals to the demodulators954-athrough954-n, respectively. Each demodulator954may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator954may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector956may obtain received symbols from all the demodulators954-athrough954-n, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receiver processor958may process (e.g., demodulate, deinterleave, and decode) the detected symbols, providing decoded data for the MTC device115-gto a data output, and provide decoded control information to a processor980, or memory982.

On the uplink (UL), at the wireless device115-g, a transmitter processor964may receive and process data from a data source. The transmitter processor964may also generate reference symbols for a reference signal. The symbols from the transmitter processor964may be precoded by a transmit MIMO processor966if applicable, further processed by the demodulators954-athrough954-n(e.g., for SC-FDMA, etc.), and be transmitted to the base station105-ein accordance with the transmission parameters received from the base station105-e. The transmitter processor964may be configured to identify a transmission cycle for an uplink channel, initiate a timer after a handshake with the base station105-e, and/or coordinate transmission of a keep-alive message, in accordance with the embodiments described above in conjunction with310,310-a,310-b,610,610-a, and610-binFIGS. 3A, 3B, 3C, 6A, 6B, and 6C, respectively. At the base station105-e, the UL signals from the wireless device115-gmay be received by the antennas934, processed by the demodulators932, detected by a MIMO detector936if applicable, and further processed by a receive processor938. The receive processor938may provide decoded data to a data output and to the processor940. In some embodiments, the processor940may be implemented as part of a general processor, the transmitter processor920, and/or the receiver processor938.

In some embodiments, the processor980is configured to utilize one or more timers for powering on and off various components of the wireless device115-g. In some embodiments, the processor980is configured to utilize and transmit according to an identified SR/RACH transmission cycle, DTX cycle, and or a DRX cycle mask. For example, processor980may be configured to limit transmission only during periods designated by the base station105-e, in conjunction with transmitter processor964and transmitter MIMO processor966, modulators954and antennas952. Processor980may further be configured to wake up to receive transmissions according to a DRX cycle designated by the base station105-e, through MIMO detector956and receiver processor958, de-modulators954, and antennas952.

The processor980may further be configured to initiate a timer after a handshake between the wireless device115-gand the base station105-e, and to facilitate transmission of a keep-alive handshake initiation message to the base station105-ewhen the timer expires. The processor980may further be configured to reset a timer after each handshake with the base station105-e.

FIG. 10Ais a flow chart illustrating an example of a method1000-afor implementing transmission overload control of wireless devices. For clarity, the method1000-ais described below with reference to wireless devices115shown and referenced in each of the preceding FIGS. In some implementations, the transmission overload control module310may execute one or more sets of codes to control the functional elements of the wireless device115or the devices300-a,300-b, and/or300-cto perform the functions described below.

At block1005, the wireless device115may identify a transmission cycle for an uplink channel. The transmission cycle may be determined by a base station105. The transmission cycle may include staggered periods during which various components of the wireless device115are powered on. The transmission cycle may be an aspect of a DTX cycle. The DTX cycle may use one or more timers for powering on or off and/or monitoring one or more components of, activity of, and/or inactivity of, the wireless device115. The transmission cycle may utilize a DRX cycle mask.

At block1010, the wireless device115may identify an off cycle with respect to the identified transmission cycle. The off cycle may be aspect of a DTX cycle. The wireless device115may thus refrain from transmitting during the off cycle.

At block1015, the wireless device115may transmit according to the identified transmission cycle. The wireless device115may be one of a set of devices115transmitting according to the same transmission cycle, while another wireless device115may be one of another, separate set of devices115transmitting according to a separate, staggered transmission cycle. The wireless device115may transmit according to a transmission cycle that corresponds to a DRX cycle, and the DRX cycle may be more sparse or more dense than the transmission cycle. The DRX ON durations of a DRX cycle may coincide with a DTX ON duration of a DTX cycle. The DTX cycle may have shorter or longer periods than a DRX cycle. The wireless device115may remain in RRC_CONNECTED state throughout the transmission cycle. In some cases, the wireless device115remains in RRC_CONNECTED state while in a sleep mode. In some embodiments, the wireless device115is an MTC device, such as an ultra-low power MTC device. Additionally or alternatively, the wireless devices115may be delay tolerant, where delay tolerance is defined with respect to a threshold (e.g., a threshold period of time during which the wireless device need not communicate with another wireless device or a base station without losing synchronization) Delay tolerance may thus be linked to a transmission cycle. In some embodiments, the wireless devices115may be UEs that may have long sleep cycles. The wireless device115may receive a transmission cycle and/or an off cycle from a base station105. And the wireless device115may operate according to the transmission cycle received from a base station105.

FIG. 10Bis a flow chart illustrating an example of a method1000-b, which may be an example of aspects of the method1000-a. For clarity, the method1000-bis described below with reference to the wireless devices115shown and referenced in each of the preceding FIGS. In one implementation, the transmission overload control module310may execute one or more sets of codes to control the functional elements of the wireless device115or the device300-a,300-b, and/or300-cto perform the functions described below. Method1000-bmay be an example of method1000-a.

At block1005-a, the wireless device115may identify a transmission cycle for an uplink channel. At block1010-a, the wireless device115may identify an off cycle with respect to an identified transmission cycle, during which off cycle the wireless device115refrains from transmitting. At block1015-a, the wireless device115may transmit a scheduling request or a RACH message according to the identified transmission cycle, which corresponds to a DRX cycle. At block1020, the wireless device115may utilize a DRX cycle mask, during which the wireless device115refrains from receiving during a DRX OFF period.

FIG. 11Ais a flow chart illustrating an example of a method1100-afor implementing supervision of wireless devices. For clarity, the method1100-ais described below with reference to base stations105a wireless devices115shown and referenced in the preceding FIGS. In one implementation, the supervision module610may execute one or more sets of codes to control the functional elements of the base stations105, the wireless devices115, or the device600-aand/or600-bto perform the functions described below.

At block1105, the base station105or the wireless device115may initiate a timer at the wireless device115after a handshake between the wireless device115and a base station105. The timer may be reset after each subsequent handshake. At block1110, the wireless device115may transmit a keep-alive handshake initiation message upon expiration of a timer. The keep-alive handshake initiation message may include a scheduling request (SR) or a RACH message. The wireless device115may listen to a response message or uplink grant from a base station105. The wireless device115may reply with a closing message or in a payload with a closing message. In some embodiments, the wireless devices115may be delay tolerant, which may be defined with respect to a threshold. Additionally or alternatively, delay tolerance may be linked to a transmission cycle. In some embodiments, the wireless devices115are UEs having long sleep cycles.

FIG. 11Bis a flow chart illustrating an example of a method1100-b, which may be an example of aspects of the method1100-a. For clarity, the method1100-bis described below with reference to base stations105the wireless device115shown and referenced in each of the preceding FIGS. In one implementation, the supervision module610may execute one or more sets of codes to control the functional elements of the base stations105, wireless device115or the device600-a,600-b, and/or600-cto perform the functions described below. Method1100-bmay be an example of method1100-a.

At block1105-a, a wireless device115may initiate a timer at the wireless device115after a handshake between base station105and the wireless device115. At block1110-a, the wireless device115may transmit a keep-alive message, which is an SR or a RACH message to the base station105upon the expiration of a timer. At block1115, the wireless device115listens to a response message or for an uplink grant from the base station105. At block1120, the wireless device replies with a closing message or replies in a payload with a closing message.

FIG. 12Ais a flow chart illustrating an example of a method1200-afor implementing supervision of wireless devices. For clarity, the method1200-bis described below with reference to base stations105and wireless devices115. In one implementation, the supervision module610may execute one or more sets of codes to control the functional elements of the base stations105, the wireless devices115, or the devices600-a,600-b, and/or600-cto perform the functions described below.

At block1205, a base station may determine a list of connected wireless devices115. The list of connected devices may include one or more wireless devices115that have not transmitted a keep-alive handshake initiation message (e.g., not transmitted a RACH message or a SR) within a time period determined or communicated to the base station105. At block1210, a base station may broadcast one or more messages including a list of connected wireless devices. The base station may broadcast in one or more messages based on or according to a staggered DRX cycle. A broadcast message may include only a subset of connected wireless devices115from a list of connected devices. The base station may receive a response message from a wireless device115indicating that the wireless device115is not, but should be on the list of connected devices. In some embodiments, the wireless devices115are delay tolerant, where delay tolerance is defined with respect to a threshold. Additionally or alternatively, delay tolerance may be linked to a transmission cycle. In some embodiments, the wireless devices115are UEs having long sleep cycles.

FIG. 12Bis a flow chart illustrating an example of a method1200-b, which may be an example of aspects of the method1200-a. For clarity, the method1200-bis described below with reference to base stations105wireless devices115shown and referenced in each of the preceding FIGS. In one implementation, the supervision module610may execute one or more sets of codes to control the functional elements of the base stations105, wireless device115or the devices600-a,600-b, and/or600-cto perform the functions described below. Method1200-bmay be an example of method1200-a.

At block1205-a, the base station105may determine a list of connected MTC devices that have not transmitted a keep-alive handshake initiation message within a time period. At block1210-a, the base station105may broadcast a plurality of messages based on a staggered DRX cycle so that each respective message includes a subset of connected wireless devices115from a list of connected devices.

The functions described herein may be implemented in hardware, software/firmware, or combinations thereof. If implemented in software/firmware, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software/firmware, functions described above can be implemented using software/firmware executed by, e.g., a processor, hardware, hardwiring, or combinations thereof. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.