WO2021235782A1

WO2021235782A1 - Method and system for providing seamless connectivity in a communication network

Info

Publication number: WO2021235782A1
Application number: PCT/KR2021/006099
Authority: WO
Inventors: Sweta Jaiswal; Jamsheed Manja Ppallan; Karthikeyan Arunachalam; Shiva Souhith GANTHA; Anshuman Nigam; Seongkyu Song
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2020-05-16
Filing date: 2021-05-14
Publication date: 2021-11-25

Abstract

The present disclosure discloses method and system for providing seamless connectivity in a communication network by a user equipment (UE). The method comprises identifying one or more applications in the UE with ongoing transport layer connections and allocating a unique identifier (ID) for each of the one or more applications and detecting at least one of radio link fluctuation in the communication network, inter network mobility of the UE and intra network mobility of UE. Thereafter method comprises terminating a transport layer connection associated with each of the one or more applications and retaining transport layer parameters associated with each of the one or more applications based on the unique ID, when at least one of radio link fluctuation in communication network, the inter mobility of UE and the intra mobility of UE is detected. When radio link is recovered, transport layer connections associated with each of the one or more applications are resumed based on the retained transport layer parameters or a new transport layer connection is established with retained transport layer parameters during the intra mobility of the UE or the inter mobility of UE. The present disclosure provides seamless connectivity in communication network during user mobility and frequent radio link handover scenarios.

Description

METHOD AND SYSTEM FOR PROVIDING SEAMLESS CONNECTIVITY IN A COMMUNICATION NETWORK

The present subject matter is related, in general to communication network, and more particularly, but not exclusively, to a method and system for providing seamless connectivity in a communication network.

Transmission Control Protocol (TCP) is designed to provide end-to-end reliable connection for static networks. But the present mobile devices are equipped with multiple wireless interfaces, which increases handover scenarios in these diverse network infrastructures.

The current transport layer does not support Internet Protocol (IP) mobility by default. Therefore, any change in Internet Protocol (IP) address in the network layer badly affects the ongoing TCP connections. The IP address can also change due to inter network mobility from cellular (Long-Term Evolution (LTE)/ Fifth Generation (5G)) to Wireless Fidelity (Wi-Fi) network or vice versa. But the transport layer is unaware of mobility changes in lower layer which impacts the end-to-end reliability badly. Similarly, the radio signal fluctuations in the lower layers are not notified immediately to the upper layers, which impacts the performance of transport layers significantly. Moreover, the short-range characteristics of 5G mm Wave spectrum are severely affected during mobility, especially in Non-Line of Sight (NLOS) conditions since it is easily absorbed and blocked by obstacles. Hence, it is important to appropriately handle these radio level fluctuations and take care of mobility in transport layer as well to maintain end-to-end reliability.

Currently, the existing approaches which are defined in Identity Oriented Networking (ION), MobilityFirst (MF) and Information Centric Networking (ICN) provides seamless user mobility in heterogeneous wireless technologies. However, these Non-IP solution approach defines a completely new protocol stack and need changes in all the network nodes, posing serious deployment issues. Both, Session-based Mobile Socket Layer (SMSL), and FreezeTCP are specific to TCP and do not improve upon TCP's congestion control algorithm, leading to resource underutilization. Quick UDP Internet Connection (QUIC) uses connection Identifier (ID) for connection migration during network handovers, but its TCP-like congestion control algorithm causes high handover delays while resuming the connection.

Also, the present Congestion Control algorithms use timeouts and duplicate acknowledgment parameters to detect packet loss. However, these parameters are not enough and lead to unnecessary packet retransmission and data rate reduction.

The present disclosure is directed to overcome one or more limitations stated above or any other limitation associated with the conventional arts.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

In an embodiment of the present disclosure discloses a method for providing seamless connectivity in a communication network by a user equipment (UE) is disclosed. At first, the method comprises identifying one or more applications in the UE with ongoing transport layer connections and allocating a unique identifier (ID) for each of the one or more applications; detecting at least one of radio link fluctuation in the communication network, inter network mobility of the UE and intra network mobility of the UE; terminating a transport layer connection associated with each of the one or more applications and retaining transport layer parameters associated with each of the one or more applications based on the unique ID, when at least one of the radio link fluctuation in the communication network, the inter mobility of the UE and the intra mobility of the UE is detected; and performing one of: resuming the transport layer connection associated with each of the one or more applications based on the retained transport layer parameters, when the radio link is recovered; or establishing a new transport layer connection with the retained transport layer parameters during the intra mobility of the UE or the inter mobility of the UE.

Further, the present disclosure discloses a method for providing seamless connectivity by a user equipment (UE) during mobility. The method comprises allocating a unique identifier (ID) for at least one of a plurality of ongoing transport layer connections between a network node and the UE; monitoring the network characteristics for the at least one of the plurality of ongoing transport layer connections; and applying a congestion control for the at least one of the plurality of ongoing transport layer connections if the network characteristics are below a threshold.

In an embodiment, an apparatus of a user equipment (UE) for providing seamless connectivity in a communication network is disclosed. The apparatus comprises a transceiver; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to be operated according to one of the methods.

Further, the present disclosure discloses an apparatus of a user equipment (UE) for achieving seamless connectivity during mobility. The apparatus comprises a transceiver; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to be operated according to one of the methods.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and regarding the accompanying figures, in which:

Fig. 1 illustrates an exemplary environment for providing seamless connectivity in a communication network and an exemplary representation for ID oriented Socket Layer (IoSL) between other layers according to various embodiments of the present disclosure.

Fig. 2 illustrates a block diagram of a system for providing seamless connectivity in a communication network according to various embodiments of the present disclosure.

Fig. 3 illustrates an exemplary representation illustrating operation flow of double-ended mode of IoSL, according to various embodiments of the present disclosure.

Fig. 4 illustrates an exemplary representation illustrating operation flow of single ended mode of IoSL, according to various embodiments of the present disclosure.

Fig. 5 illustrates a graph indicating difference in response of IoSL and standard TCP during signal outrage, according to various embodiments of the present disclosure.

Fig. 6 illustrates an exemplary representation for ns-3 simulation setup, according to various embodiments of the present disclosure.

Fig. 7 illustrates a graph illustrating upload scenario with IoSL on a sender side and a graph illustrating download scenario with IoSL on a receiver side, according to various embodiments of the present disclosure.

Fig. 8 illustrates a performance analysis of double-ended mode IoSL during vertical handover over TCP transport protocols, a performance analysis of double-ended mode IoSL during vertical handover over SCTP transport protocols and a performance analysis of double-ended mode IoSL during vertical handover over MPTCP transport protocols, according to various embodimentsof the present disclosure.

Fig. 9 illustrates a flowchart of a method for providing seamless connectivity in a communication network, and a flowchart of a method for providing seamless connectivity in a communication network, according to various embodiments of the present disclosure.

Fig. 10 illustrates a block diagram of an exemplary computer system for implementing embodiments consistent with the present disclosure.

It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether such computer or processor is explicitly shown.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the specific forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

The terms "comprises", "comprising", "includes", "including" or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

The present disclosure relates to a method and a system for providing seamless connectivity in a communication network. The present disclosure discloses the aspect of designing an easily deployable mobility solution called ID oriented Socket Layer (IoSL) (also referred as system). IoSL communicates with lower layers of network model to identify user mobility and handover scenarios and effectively controls the transport layer for optimal utilization of available bandwidth. In an embodiment, IoSL may be implemented in major transport layer protocol such as TCP, Stream Control Transmission Protocol (SCTP) and Multipath TCP (MPTCP) regardless of its characteristics. IoSL is designed as a transparent middleware solution which does not require any changes in the applications, network protocols, or middle boxes making it easily deployable. Further, IoSL has been designed to operate in both double-ended and single-ended modes. IoSL falls back to the single ended mode if only one of the end hosts (UE or server) supports IoSL. IoSL maintains the ID layer between application and transport layer for providing seamless connectivity to end devices in the communication network.

In an embodiment, the system is configured in a User Equipment (UE). The system comprises an ID Management System (IDMS), wherein the IDMS identifies one or more applications in the UE with ongoing transport layer connections and assigns a unique Identifier (ID) for each of the one or more applications. As an example, applications configured in the UE comprises information associated with the call connection, streaming a video, uploading/downloading data and vehicular communication. The unique identifier for each transport layer connections are generated by the IDMS when the application request for a transport layer connection.

The system also comprises a Network State Management System (NSMS), wherein the NSMS detects at least one of radio link fluctuation in the communication network, inter network mobility of the UE and intra network mobility of the UE by monitoring network state of the transportation layer in real-time through cross-layer communication with lower layers. The detected radio link fluctuation is monitored based on channel quality parameters comprising at least one of a Channel Quality Indicator (CQI), Signal-to-Interference-plus-Noise Ratio (SNR/SINR), Reference Signal Receive Power RSRP, Reference Signal Received Quality (RSRQ).

The system also comprises a Mobility and Connection Control System (MCCS), wherein the MCCS terminates transport layer connection associated with each of the one or more applications and retains transport layer parameters associated with each of the one or more applications when at least one of the radio link fluctuation in the communication network, inter mobility of the UE and intra mobility of the UE is detected. Further, the MCCS resumes transport layer connections with the retained transport layer parameters when the radio link is recovered or establishes a new transport layer connection with the retained transport layer parameters during intra or inter mobility of the UE. The transport layer parameters comprises information associated with the Round Trip Time (RTT), throughput, Retransmission Time Out (RTO) for each transport layer connection. The transport layer parameters are retained based on the unique identifier of each of the one or more applications, for providing seamless connectivity in the communication network.

In this manner, the present disclosure discloses a method and an apparatus for providing seamless connectivity in a communication network during user mobility and frequent radio link handover scenarios by configuring IoSL. IoSL monitors the access-network, maintains a unique identifier and gathers important transport layer parameters using cross-layer communication for the transport layer connections to achieve improved throughput and Quality-of-Service (QoS) with enhanced user experience in mobility scenarios.

Fig. 1(a) illustrates an exemplary environment for providing seamless connectivity in a communication network according to various embodiments of the present disclosure.

The environment comprises a system 103 configured in a UE 100, one or more applications 101, application 1 101₁ to application n 101_n (collectively referred to as one or more applications 101 or applications 101) and a server 105. As an example, the one or more applications 101 may include, but not limited to, call connection, streaming a video, uploading/downloading data, and vehicular communication. For each of the one or more applications 101, a TCP connection is established with the server 105 through the system 103.

As an example, a user may be streaming a video as one of the applications 101, application 1 101₁ and moving from point A network to point B network, where point A is connected to 5G network and point B connected to Wi-Fi network. The application 1 101₁ is associated with a TCP connection. In one embodiment, whenever there is a radio blockage, the available bandwidth reduces and may cause packet losses. TCP goes into slow start phase (given the blockage is long enough) considering the packet losses are due to network congestion.

In an embodiment, the slow ramp up of the congestion window post blockage causes bandwidth underutilization. The user may see a decrease in the video resolution or quality even after the radio link recovers. Also, when the user switches from the cellular network to Wi-Fi network, the existing TCP connections are terminated. The application 101, application 1 101₁ needs to create a new TCP connection and start again from the slow start phase. This may also to lead to buffering and reduction in the video resolution. To overcome this constraint, the present disclosure discloses a system 103 which may be configured in the UE 100 for providing seamless connectivity in a communication network.

Fig. 1(b) illustrates an exemplary representation for ID oriented Socket Layer (IoSL) between other layers according to various embodiments of the present disclosure.

As shown in Fig. 1(b), the IoSL 103 is a transparent middleware which runs in between application layer 107 and transport layer 109 which is with other layers such as network layer 111, radio access layer 113. The IoSL 103 establishes transport layer connections for each of one or more applications 101 configured in UE 100. The IoSL 103 maintains unique ID for each of the one or more applications 101. During radio link layer fluctuations, IoSL 103 terminates the ongoing transport layer connections and resumes it after the link is recovered. During inter mobility of the network, IoSL 103 re-establish transport layer connections and restores transport layer parameters for quick recover of the transport layer connections. During Intra-network scenario, IoSL 103 predicts a radio blockage using cross layer information and suspends the TCP connections until the link recovers. After the radio link recovers, IoSL 103 resumes the TCP connection and therefore avoids drastic reduction of the congestion window. Therefore, after the radio link recovery, the video resolution does not drop, and the available bandwidth is effectively utilized. In the Inter-network scenario, when the user switches from the cellular network to Wi-Fi network, IoSL 103 establishes a new TCP connection with restored transport layer parameters and maps it to the application 101. Thus, it transparently recreates the transport layer connection and avoids TCP slow start without hampering the user experience.

In an embodiment, the IoSL 103 is designed to operate in two different modes, namely double-ended and single-ended modes. In the double-ended mode, it does the peer process communication and assists the transport layer 109 at both ends of the devices (UE) for quick recovery of the transport layer connections. In single-ended mode, it acts as a device-only solution and enables cross-layer communication for enhanced transport layer communication. IoSL 103 operates in double-ended mode, by default, to support seamless connectivity during vertical as well as horizontal.

In an embodiment, the IoSL 103 comprises an ID Management System (IDMS) 124, a Network State Management System (NSMS) 125 and a Mobility and Connection Control System (MCCS) 126 as shown in Fig.2.

In an embodiment, the IDMS 124 may be configured to identify one or more applications 101 in the UE 100 with ongoing transport layer connections using ID manager and assigns a unique Identifier (ID) for each of the one or more applications 101. The assigned unique identifiers are stored in a database associated with the IDMS 124. The IDMS 124 assigns the unique identifier based on 5-tuple values comprising source/destination IP address, port and protocol and connection parameters obtained from cross-layer communication with lower layers associated with transport layer 109 of the UE 100. When application 101 request for a transport layer connection, IDMS 124 allocates and maps the unique identifier to the requested application 101 socket. wherein the transport layer parameters comprises Round Trip Time (RTT), throughput, Retransmission Time Out (RTO) for each transport layer connection. Also, it terminates the unique identifier from the application socket when the transport layer connection is terminated. The IDMS 124 comprises peer process communicator for communicating with one or more peer applications 101.

In an embodiment, the NSMS 125 is configured to detect at least one of radio link fluctuation in the communication network, inter network mobility of the UE 100 and intra network mobility of the UE 100 by monitoring network state of the transportation layer in real-time through cross-layer communication with lower layers such as radio access layer 113. The NSMS 125 also monitors radio channel characteristics of the communication network in real-time through cross layer communication with lower layers associated with transport layer 109 of the UE 100. The NSMS 125 detects the radio link fluctuation by monitoring channel quality parameters comprising at least one of a Channel Quality Indicator (CQI), Signal-to-Interference-plus-Noise Ratio (SNR/SINR), Reference Signal Receive Power RSRP, Reference Signal Received Quality (RSRQ). Further, the NSMS 125 monitoring comprises identifying inter and intra network mobility of the UE 100.

In an embodiment, the MCCS 126 is configured to terminate transport layer connection associated with each of the one or more applications 101 and retains transport layer parameters associated with each of the one or more applications 101 when at least one of the radio link fluctuation in the communication network, inter mobility of the UE 100 and intra mobility of the UE 100 is detected. The transport layer parameters comprises Round Trip Time (RTT), throughput, Retransmission Time Out (RTO) for each transport layer connection. Thereafter, the MCCS 126 is configured to perform one of resuming transport layer connections with the retained transport layer parameters when the radio link is recovered or establishing a new transport layer connection with the retained transport layer parameters during intra or inter mobility of the UE 100. The transport layer parameters are retained based on the unique identifier of each of the one or more applications 101, for providing seamless connectivity in the communication network. The retained transport layer parameters are stored in data cache.

The MCCS 126 regulates the transport layer connections using connection manager and connection controller based on information received from the NSMS 125 and modify the congestion control parameters. The MCCS 126 adjusts the transport layer parameters such as the congestion window (cwnd) and receive window (rwnd) for optimal utilization of the available bandwidth. The MCCS 126 suspends and resumes ongoing transport layer connections based on the network conditions and the MCCS 126 restores network parameters for the newly migrated transport layer connections.

Thereafter, in one embodiment, the MCCS 126 resumes transport layer connections with the retained transport layer parameters when the radio link is recovered. The MCCS 126 adjusts flow and congestion control of a transport layer 109 in the UE 100 during the radio link fluctuation. This is performed by adjusting congestion window and receiver window for each transport layer connection based on Signal to Noise Ratio (SINR) between the UE 100 and the server 105. In another embodiment, the MCCS 126 establishes a new transport layer connection with the retained transport layer parameters during intra or inter mobility of the UE 100. The usage of predefined factors is exampled in detail in the exemplary scenario.

As shown in Fig. 3, at step (1) when application 101 request for a transport layer connection, IDMS 124 creates/generates a TCP connection and allocates a unique identifier. The assigned unique ID is based on 5-tuple values comprising source/destination IP address, port and protocol and connection parameters obtained from cross-layer communication with lower layers associated with transport layer 109 of the UE 100. At step (2) NSMS 125 detects mobility of the UE 100 while the application 101 is active either as intra-network (step 2a) or as inter-network (step 2b). The NSMS 125 monitors channel quality parameters which includes, but not limited to, CQI, SNR/SINR, RSRP, RSRQ. At step 3(a) MCCS 126 suspends the ongoing transport layer connection when radio link disconnection is predicted by the NSMS 125. At step 3(b) when inter-mobility is detected while moving to a different network (5G and Wi-Fi), the MCCS 126 stores the transport layer parameters and terminates the connections. At step 4(a) MCCS 126 resumes the transport layer connections with the retained transport layer parameters when the radio link is recovered. At step 4(b) in case of a terminated connection, the MCCS 126 establishes a new transport layer connection with the retained transport layer parameters during intra or inter mobility of the UE 100.

The operation flow of the single-ended mode is similar to that of double-ended variant, except for peer process communication and support for vertical mobility since it is installed only at the device side. Hence, single-ended IoSL 103 guarantees the smooth recovery of connections during horizontal handover.

In an embodiment, the IoSL 103 operates in double ended mode by default and controls transport layer connections at both ends i.e., client and server 105. In default mode, the IoSL 103 continuously communicates with the peer process and exchanges the transport control parameters, such as cwnd, rwnd, with both ends to assist the transport layer 109 for optimal utilization of the available network. If the peer end does not support IoSL 103, the operation drops back to the single-ended mode and regulates the transport layer connections at the one end of the device. Moreover, IoSL 103 is designed as a transparent middleware solution between application layer 107 and transport layer 109 and which does not require any changes in the socket programming layer, existing applications, and middleboxes.

In an embodiment, when the application 101 configured in the UE 100 sends data over the transport layer connection, IoSL 103 controls the congestion window based on the radio layer parameters received through cross-layer communication. In an embodiment, when the application 101 receives data over the transport layer connection, IoSL 103 modifies the receive window and controls the sender through window advertisement. Whenever a handover or radio link-layer disconnection is detected, IoSL 103 controls the congestion and flow control parameters for avoiding packet loss and excessive buffering in the queue. Also, IoSL 103 ignores the RTT value calculated during the temporary radio link fluctuations and optimizes the cumulative RTT for the better utilization of available bandwidth. In the present disclosure, IoSL 103 analyzes the radio access layer 113 parameters and controls the transport layer 109 for the improved performance in the wireless network.

In an embodiment, IoSL 103 is configured in UE 100 to operate independently of the underlying transport layer protocols such as Transmission Control Protocol (TCP), Stream Control Transmission Protocol (SCTP), and Multipath TCP (MPTCP), wherein the transport layer protocols use similar congestion and flow control mechanisms. In an embodiment, adjusting the flow and congestion control comprises information associated with the adjusting congestion window and receiver window for each transport layer connection based on Signal to Noise Ratio (SINR) between the UE 100 and the server 105 associated with the UE 100. In an embodiment, SCTP's congestion and flow control mechanisms are designed for association level only and not supported for stream level. But IoSL 103 generates and maps the unique identifier to each application 101 by IDMS 124 configured in the system 103 for only SCTP associations, for resuming and restoring SCTP transport layer parameters. In an embodiment, MPTCP creates sub-flows over multiple interfaces for path redundancy, and each sub flows of MPTCP have congestion and flow control mechanisms. But IoSL 103 creates an ID for each sub-flow of the MPTCP connection for the fast recovery of transport layer parameters. Therefore, IoSL 103 disclosed in the present disclosure provides support for transport layer protocols for enhanced end-to-end connectivity.

In an embodiment, during horizontal handover, when the UE 100 moves from one access point network to another access point network, IoSL 103 terminates the transport layer connections and MCCS 126 stores the transport layer connection parameters at the server 105 associated with UE 100. In an embodiment, when the horizontal handover is completed, the IoSL 103 resumes the transport layer connections and restores the transport layer parameters for the quick recovery of the previous network state. In an embodiment, during vertical handover, the on-going transport layer connections are suspended, due to IP variation in the network layer 111. When the transport layer connection resumes back after the vertical handover, the IoSL 103 recognizes the transport layer connection and restores the network state through its stored characteristics in the ID layer for providing seamless connectivity in the communication network.

In an embodiment, the IoSL 103 improves congestion and flow control mechanisms during link layer fluctuations and also during blockage and handovers. As an example, consider TCP CUBIC as the transport protocol, when precluding idle time during data flow and optimal bandwidth utilization, the window size (W) may be equal to the bandwidth-delay product (BDP) as shown in below equation 1.

...(1)

We assume that the receive window (rwnd) does not limit the window size and the available window (W) is determined by the congestion window (cwnd). RTT and available bandwidth is estimated over the wireless link to obtain BDP, wherein RTT is calculated with the reception of each ACKs using timestamps. The available bandwidth can be assessed using cross-layer communication with the lower layer. As an example, the algorithm 1 shows pseudo-code of IoSL 103 congestion control algorithm which illustrates how the congestion window is updated during radio link transport layer fluctuations.

In an embodiment, when the SINR values are low due to the radio link fluctuation in the lower layer, it is assumed that the wireless link is the bottleneck and therefore, the IoSL 103 utilize the scaled estimated BDP value to update cwnd. Further, excessive buffering and packet loss may avoided, when cwnd is not allowed to increase beyond the estimated BDP value. In the present disclosure, the IoSL 103 regulates the congestion control parameters for better utilization of available bandwidth.

In an embodiment, IoSL 103 adjust the value of the maximum receive window and default receive window size (rwnd) based on the cross-layer information to improve the downlink throughput performance. During the transport layer connection establishment, IoSL 103 initializes the maximum receive window size based on the estimated BDP and updates the receive window (rwnd) at regular intervals during the handover and blockage scenarios. In the present disclosure, IoSL 103 controls the data flow from the UE 100 and improves the data flow control mechanism in the transport layer 109.

In an embodiment, the IoSL 103 predicts the signal blockage or handover as illustrated below.

The IoSL 103 maintains a weighted average of the SINR values as expressed in equation 2 below.

...(2)

Where, SINR^t is the present value of SINR,

is the average calculated at time 't', and

is the previous value of the average. If the following condition is true, radio link disconnection is predicted.

...(3)

where

and ε are threshold parameters and τ is adjusted according to the channel behaviour. Based on these parameters may determine steepness of drop in SINR value used for predicting a disconnection.

In an embodiment, when IoSL 103 is operating on the receiver side and a radio link disconnection is predicted, IoSL 103 enters a freeze mode and advertises zero receive window (rwnd = 0) to the sender. The sender upon receiving a zero-window advertisement, freezes its congestion window, re-transmission timers, and enters into persist mode. In case of an incorrect prediction (false alarm) or after the link recovers, the receiver as an example sends three duplicate ACKs corresponding to the last received packet to restart the radio link connection.

In an embodiment, when the IoSL 103 is operating on the sender side, it regulates the congestion window based on the lower-layer network conditions. It stores the transport layer parameters in its socket management layer that includes ssthresh, cwnd, rwnd, and many more. Also, the IoSL 103 retrieves transport layer parameters using the unique identifier for regulating the transport layer connections. The IoSL 103 resumes transport layer connection, when the radio link condition improves or, the handover is completed and IoSL 103 uses the stored transport layer parameters to resume or restart the connection. In the present disclosure, IoSL 103 effectively controls the congestion state and avoids the transport layer 109 from going into slow start during blockage or a handover event.

An example scenario is considered where there is sudden radio link disconnection and, the radio link recovers to the previous state. In such cases in standard TCP without IoSL 103 would enter a fresh slow start (cwnd = 1). On the other hand, when IoSL 103 is enabled, it terminates all the transport layer connections and freezes the congestion window values. Once the radio link recovers, IoSL 103 resumes all the transport layer connections, restoring the congestion window values as they were before the radio link disruption. The response for the standard TCP and the IoSL 103 for this scenario is shown in Fig.5. The additional number of data segments that IoSL 103 sends by the time the TCP recovers to the original state may be approximately calculated.

As an example, let W be the stable congestion window size at the peak before the radio link disconnection. When timeout occurs, TCP will start growing its window exponentially during a slow start phase until it reaches a threshold (ssthresh), which is set as 0.7W (beta cubic = 0.7) after the timeout. Once the threshold ssthresh value reaches 0.7W, then TCP shifts to the congestion avoidance phase where the window grows in a concave cubic fashion until it reaches the peak value (= W).

In the slow start phase, TCP will start with the congestion window of 1 MSS and double the window with each RTT. Therefore, it will take log₂(0.7W) RTT for the window size to reach 0.7W. In an embodiment, the number of RTT taken in the congestion avoidance phase to reach the prior window value of W be ε expressed in equation 4.

...(4)

where, beta cubic = 0.7 and C = 0.4. Further, calculate the extra packets sent using IoSL 103 is

...(5)

In an embodiment, if a frequent blockage scenario is considered to calculate the average Throughput Improvement (TI) by IoSL 103, wherein the next radio link disconnection occurs just after the standard TCP recovers from the previous radio link termination. First the additional data is defined as:

...(6)

Where

is the amount of additional data transferred. Hence, the Throughput Improvement (TI) is mathematically expressed as

...(7)

Since W is directly proportional to BDP for the end-to-end path, the equation 7 shows that IoSL 103 is more beneficial for high BDP connections and also, as the frequency of blockage or handover increases, higher will be the improvement in throughput.

Fig. 6 illustrates an exemplary representation for ns-3 simulation setup, according to various embodiments of the present disclosure, which discloses a plot of time taken for reconnection of a terminated radio link connection. The simulation setup as shown in Fig. 6 includes frequent radio link blockages, vertical and horizontal handovers for both single and double-ended modes with various transport layer protocols. As an example, we may consider that the simulation setup consists of both 5G Microcell and Wi-Fi Aps networks configured at every 100 meters, and the user may move back and forth between any two APs, as shown in the Fig. 6 connecting to a server 105. Using this setup which has throughput capacity and handover frequency, a goodput improvement for downloading files of various sizes is tested, when there is link quality disruption during handover causing disconnection.

The simulation setup is configured in two different simulation scenarios and performance of IoSL 103 configured in the UE 100 is measured. In the first the performance of IoSL 103 during frequent radio link blockages and radio link disconnections caused by external objects and horizontal handovers is evaluated. For this experiment, two user devices are configured one with IoSL 103 in single-ended mode and the other without IoSL 103. Further, the wireless links get disconnected due to radio link blockages as the users move from one network to another network, which causes a signal outage in both the UE 100 devices and results in a significant throughput drop.

Fig. 7(a) illustrates a graph illustrating upload scenario with IoSL on a sender side, according to various embodiments of the present disclosure, wherein the IoSL 103 recovers the network state by regulating cwnd whereas the UE 100 configured without IoSL 103 takes a long time to reach network capacity due to the limitation of the congestion control mechanism. In case of the download scenario, IoSL 103 identifies the radio link termination and terminates the data flow by sending a zero receive window (rwnd = 0) advertisement to the sender.

Fig. 7(b) illustrates a graph illustrating download scenario with IoSL on a receiver side, according to various embodiments of the present disclosure. As shown in Fig.7B, IoSL 103 quickly recovers the connection as the link is re-established by sending triple duplicate ACKs to the sender, whereas the device without IoSL 103 suffers due to packet loss and retransmission timeout. Hence, this experiment proves that the IoSL 103 efficiently regulates the transport layer parameters for better utilization of available bandwidth during blockage and horizontal handover scenarios.

In another embodiment, the IoSL 103 is also evaluated for double-ended mode with vertical handover scenarios.

Fig. 8(a) illustrates a performance analysis of double-ended mode IoSL during vertical handover over TCP transport protocols, according to various embodiments of the present disclosure. Fig. 8(a) shows the fast radio link connection recovery of TCP with IoSL 103 in comparison with the standard TCP. In case of standard TCP, the radio link connection is terminated and recovered radio link slowly, whereas, with IoSL 103 configured in UE 100, the TCP connection is recreated and recovered quickly, providing better throughput. In an embodiment, IoSL 103 performance is also evaluated over SCTP, wherein the UE's 100 are configured to connect with 5G network as primary and Wi-Fi network as a secondary path initially, and then the 5G radio link goes down.

Fig. 8(b) illustrates a performance analysis of double-ended mode IoSL during vertical handover over SCTP transport protocols, according to various embodiments of the present disclosure. As shown in Fig. 8(b), the UE 100 with IoSL 103 SCTP adjusts its transport layer parameters and recovers its network state in Wi-Fi quickly, managing to better throughput. But in case of MPTCP transport protocol, the UE 100 device is configured to connect with both Wi-Fi and 5G network initially, and then the 5G radio link goes down.

Fig. 8(c) illustrates a performance analysis of double-ended mode IoSL during vertical handover over MPTCP transport protocols, according to various embodimentsof the present disclosure.

As shown in the Fig. 8(c), the IoSL 103 device instantiates the radio link network state much faster than the standard MPTCP. Hence, the present disclosure, IoSL 103 adjusts the transport layer parameters and recovers much faster during the handovers. In an embodiment, the present disclosure is applicable in cases where the UE 100 is configured with 6G as well.

Fig. 9(a) illustrates a flowchart of a method for providing seamless connectivity in a communication network, according to various embodiments of the present disclosure.

As illustrated in Fig. 9(a), the method comprises one or more blocks for providing seamless connectivity in a communication network by a system 103. The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 901, the method comprises identifying one or more applications 101 in the UE 100 with ongoing transport layer connections and assigning a unique Identifier (ID) for each of the one or more applications 101. The unique ID is assigned to each of the one or more applications 101 in the UE 100 with ongoing transport layer connections by an ID management system (IDMS) 124 configured in the system 103. Further, the unique ID mapped to each of the one or more applications 101 are stored at a server 105 associated with the UE 100.

At block 903, the method comprises detecting at least one of radio link fluctuation in the communication network, inter network mobility of the UE 100 and intra network mobility of the UE 100 by monitoring network state of the transportation layer in real-time through cross-layer communication with lower layers. Monitoring the network state is performed by a Network State Management system (NSMS) 125 configured in the system 103. Further, the radio link fluctuation is detected by monitoring channel quality parameters comprising at least one of a Channel Quality Indicator (CQI), Signal-to-Interference-plus-Noise Ratio (SNR/SINR), Reference Signal Receive Power (RSRP), and Reference Signal Received Quality (RSRQ).

At block 905, the method comprises terminating transport layer connection associated and retaining transport layer parameters associated of the applications 101 when the radio link fluctuation in the communication network, inter mobility of the UE 100 and intra mobility of the UE 100 is detected. The termination process is performed by Mobility and Connection Control system (MCCS) 126 configured in the system 103. Further, the MCCS 126 stores the transport layer parameters, adjusts flow and congestion control of a transport layer 109 in the UE 100 during the radio link fluctuation and terminates the connections when inter mobility of the UE 100 is detected.

At block 907, the method comprises resuming transport layer connections with the retained transport layer parameters when the radio link is recovered. At block 909, the method comprises establishing a new transport layer connection with the retained transport layer parameters during intra or inter mobility of the UE 100, wherein the transport layer parameters are retained based on the unique identifier of each of the one or more applications 101, for providing seamless connectivity in the communication network.

Fig. 9(b) illustrates a flowchart of a method for providing seamless connectivity in a communication network, according to various embodiments of the present disclosure.

As illustrated in Fig. 9(b) the method comprises one or more blocks for providing seamless connectivity in a communication network by a system 103. The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.

At block 911, the method comprises allocating a unique identifier for at least one of a plurality of ongoing connections between a network node and a UE 100, wherein the movement of the UE 100 is one of inter network or intra network. The allocation of the unique ID is performed by an ID Management System (IDMS) 124 of the system 103.

At block 913, the method comprises monitoring the network characteristics or radio channel for the at least one identified connection. The monitoring of the network characteristics is performed using a Network State Management System (NSMS) 125 of the system 103 which monitors the state of the network for cross-layer communication with lower layers. The radio channel characteristics comprises at least one of a CQI, SNR/SINR, RSRP and RSRQ.

At block 915, the method comprises applying a congestion control for the at least one identified connections if the network characteristics are below a threshold. The regulation of congestion is performed using a Mobility and Connection Control System (MCCS) 126 of the system 103 and MCCS 126 suspends the ongoing transport layer connections when radio link disconnection is predicted. The MCCS 126 stores the transport layer parameters and terminates the connections when inter mobility of the UE 100 is detected.

Computer System

Fig.10 illustrates a block diagram of an exemplary computer system 1000 for implementing embodiments consistent with the present disclosure. In an embodiment, the computer system 1000 is used for providing seamless connectivity in a communication network. The computer system 1000 may include a central processing unit ("CPU" or "processor") 1002. The processor 1002 may comprise at least one data processor for executing program components for executing user or system-generated business processes. The processor 1002 may include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

The processor 1002 may be disposed in communication with one or more input/output (I/O) devices (1011 and 1012) via I/O interface 1001. The I/O interface 1001 may employ communication protocols/methods such as, without limitation, audio, analog, digital, stereo, IEEE-1394, serial bus, Universal Serial Bus (USB), infrared, PS/2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), high-definition multimedia interface (HDMI), Radio Frequency (RF) antennas, S-Video, Video Graphics Array (VGA), IEEE 802.n /b/g/n/x, Bluetooth, cellular (e.g., Code-Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System For Mobile Communications (GSM), Long-Term Evolution (LTE) or the like), etc. Using the I/O interface 1001, the computer system 1000 may communicate with one or more I/

O devices

1011 and 1012.

In some embodiments, the processor 1002 may be disposed in communication with a communication network 1009 via a network interface 1003. The network interface 1003 may communicate with the communication network 1009. The network interface 1003 may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10/100/1000 Base T), Transmission Control Protocol/Internet Protocol (TCP/IP), token ring, IEEE 802.11a/b/g/n/x, etc.

The communication network 1009 can be implemented as one of the several types of networks, such as intranet or Local Area Network (LAN) and such within the organization. The communication network 1009 may either be a dedicated network or a shared network, which represents an association of several types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), Wireless Application Protocol (WAP), etc., to communicate with each other. Further, the communication network 1009 may include a variety of network devices, including routers, bridges, servers, computing devices, storage devices, etc.

In some embodiments, the processor 1002 may be disposed in communication with a memory 1005 (e.g., RAM 1013, ROM 1014, etc. as shown in Fig. 10) via a storage interface 1004. The storage interface 1004 may connect to memory 1005 including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as Serial Advanced Technology Attachment (SATA), Integrated Drive Electronics (IDE), IEEE-1394, Universal Serial Bus (USB), fiber channel, Small Computer Systems Interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, Redundant Array of Independent Discs (RAID), solid-state memory devices, solid-state drives, etc.

The memory 1005 may store a collection of program or database components, including, without limitation, user /application 1006, an operating system 1007, a web browser 1008, mail client 1015, mail server 1016, web server 1017 and the like. In some embodiments, computer system 1000 may store user /application data 1006, such as the data, variables, records, etc. as described in this invention. Such databases may be implemented as fault-tolerant, relational, scalable, secure databases such as Oracle^R or Sybase^R.

The operating system 1007 may facilitate resource management and operation of the computer system 1000. Examples of operating systems include, without limitation, APPLE MACINTOSH^R OS X, UNIX^R, UNIX-like system distributions (E.G., BERKELEY SOFTWARE DISTRIBUTION^TM (BSD), FREEBSD^TM, NETBSD^TM, OPENBSD^TM, etc.), LINUX DISTRIBUTIONS^TM (E.G., RED HAT^TM, UBUNTU^TM, KUBUNTU^TM, etc.), IBM^TM OS/2, MICROSOFT^TM WINDOWS^TM (XP^TM, VISTA^TM/7/8, 10 etc.), APPLE^R IOS^TM, GOOGLE^R ANDROID^TM, BLACKBERRY^R OS, or the like. A user interface may facilitate display, execution, interaction, manipulation, or operation of program components through textual or graphical facilities. For example, user interfaces may provide computer interaction interface elements on a display system operatively connected to the computer system 400, such as cursors, icons, check boxes, menus, windows, widgets, etc. Graphical User Interfaces (GUIs) may be employed, including, without limitation, APPLE MACINTOSH^R operating systems, IBM^TM OS/2, MICROSOFT^TM WINDOWS^TM (XP^TM, VISTA^TM/7/8, 10 etc.), Unix^R X-Windows, web interface libraries (e.g., AJAX^TM, DHTML^TM, ADOBE^® FLASH^TM, JAVASCRIPT^TM, JAVA^TM, etc.), or the like.

Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present invention. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, nonvolatile memory, hard drives, Compact Disc (CD) ROMs, Digital Video Disc (DVDs), flash drives, disks, and any other known physical storage media.

In an embodiment, the present disclosure provides a method and system for providing seamless connectivity in a communication network.

In an embodiment, the present disclosure implements a IoSL layer which enables fast handover and seamless mobility in transport layer in real-time services.

In an embodiment, the present disclosure discloses IoSL which improves the data sending rate with modified congestion control using radio link transport layer parameters and guarantees the smooth recovery of connections during handover, especially horizontal handover.

In an embodiment, the present disclosure is an easy to deploy end-to-end middleware approach to improve end user throughput during network quality disruption or user mobility scenarios.

The present disclosure uses cross-layer information to detect current network status and channel quality, which helps in preventing unnecessary packet retransmission.

In the present disclosure, IoSL predicts inter and intra-network handovers as well as link disruptions and enables the transport layer session continuity without hampering user experience.

In the present disclosure, IoSL improves data sending rate with modified congestion control using link-layer parameters and guarantees smooth recovery of connections during handover, especially horizontal handover.

In the present disclosure, IoSL provides a well-designed mobility solutions to achieve seamless migration over heterogeneous networks with improved data sending rate and throughput.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

When a single device or article is described herein, it will be clear that more than one device/article (whether they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether they cooperate), it will be clear that a single device/article may be used in place of the more than one device or article or a different number of devices/articles　may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.　

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

A method for providing seamless connectivity in a communication network by a user equipment (UE), the method comprising:

identifying one or more applications in the UE with ongoing transport layer connections and allocating a unique identifier (ID) for each of the one or more applications;

detecting at least one of radio link fluctuation in the communication network, inter network mobility of the UE and intra network mobility of the UE;

terminating a transport layer connection associated with each of the one or more applications and retaining transport layer parameters associated with each of the one or more applications based on the unique ID, when at least one of the radio link fluctuation in the communication network, the inter mobility of the UE and the intra mobility of the UE is detected; and

performing one of:

resuming the transport layer connection associated with each of the one or more applications based on the retained transport layer parameters, when the radio link is recovered; or

establishing a new transport layer connection with the retained transport layer parameters during the intra mobility of the UE or the inter mobility of the UE.
The method of claim 1, wherein the transport layer parameters comprises round trip time (RTT), throughput, retransmission time out (RTO) for each transport layer connection; and

wherein the radio link fluctuation is detected by monitoring channel quality parameters comprising at least one of a channel quality indicator (CQI), signal-to-Interference-plus-noise ratio (SNR/SINR), reference signal receive power (RSRP), reference signal received quality (RSRQ).
The method of claim 1, further comprises adjusting a flow of a transport layer in the UE and congestion control of the transport layer in the UE during the radio link fluctuation; and

wherein adjusting the flow and the congestion control comprises adjusting a congestion window and a receiver window for each transport layer connection based on signal to noise ratio (SINR) between the UE and a server associated with the UE.
The method of claim 1, wherein the unique ID is allocated to each of the one or more applications by an ID management system configured in the UE;

wherein the unique ID mapped to each of the one or more applications are stored at a server associated with the UE; and

wherein while resuming the transport layer connections or while establishing the new transport layer connection, the server retains the transport layer parameters based on the unique ID for each of the one or more applications.
The method of claim 1, wherein detecting the at least one of radio link disconnection, the inter mobility of the UE and the intra mobility of the UE comprises monitoring a network state of a transportation layer in real-time through cross-layer communication with lower layers, wherein monitoring the network state is performed by a network state management system configured in the UE;

wherein the termination of the transport layer connection and the retaining transport layer parameters is performed by mobility and connection control system configured in the UE;

wherein the detecting the radio link fluctuation comprises monitoring radio channel characteristics of the communication network in real-time through cross layer communication with lower layers associated with transport layer of the UE; and

wherein the allocating the unique ID is based on 5-tuple values comprising source/destination IP address, port and protocol and connection parameters obtained from cross-layer communication with lower layers associated with transport layer of the UE.
A method for providing seamless connectivity by a user equipment (UE) during mobility, the method comprising:

allocating a unique identifier (ID) for at least one of a plurality of ongoing transport layer connections between a network node and the UE;

monitoring the network characteristics for the at least one of the plurality of ongoing transport layer connections; and

applying a congestion control for the at least one of the plurality of ongoing transport layer connections if the network characteristics are below a threshold.
The method of claim 6, wherein a movement of the UE is one of an inter network or an intra network,

wherein the UE is undergoing a horizontal handover or a vertical handover; and

wherein monitoring the network characteristics comprises identifying inter network mobility of the UE and intra network mobility of the UE.
The method of claim 6, wherein the allocation of the unique ID is performed by an ID management system (IDMS) configured in the UE;

wherein the IDMS allocates unique ID to each connection flow of a transport layer;

wherein the monitoring of the network characteristics is performed using a network state management system (NSMS) configured in the UE;

wherein monitoring the network characteristics includes monitoring at least one of a channel quality indicator (CQI), signal-to-Interference-plus-noise ratio (SNR/SINR), reference signal receive power (RSRP), reference signal received quality (RSRQ); and

wherein the NSMS monitors the state of the network for cross-layer communication with lower layers.
The method of claim 6, wherein a regulation of the congestion control is performed using a mobility and connection control system (MCCS) configured in the UE.
The method of claim 9, wherein the MCCS suspends the ongoing transport layer connections when a radio link disconnection is predicted; and

wherein the MCCS stores transport layer parameters and terminates the ongoing transport layer connections when inter mobility of the UE is detected.
The method of claim 6, wherein the ongoing transport layer connections during inter-network mobility is handled by:

communicating with a peer process with a server associated with the UE;

authenticating and exchanging control data with the peer process;

managing to maintain transport layer parameters during connection recreation after an inter-network mobility handover; and

providing the seamless connectivity by restoring the state of the ongoing transport layer connections before the inter network mobility.
The method of claim 6, wherein the ongoing transport layer connections during intra-network mobility is handled by:

identifying the ongoing transport layer connections and suspending the transport layer connections before a handover;

storing existing lower layer transport layer parameters before the handover;

monitoring the network during the handover;

resuming the ongoing transport layer connections after the handover is complete; and

adjusting the transport layer parameters to resume the ongoing transport layer connections to previous state.
The method of claim 6, wherein the transport layer connections during a radio link disconnection is handled by:

monitoring the network closely to distinguish the radio link disconnection and a handover;

continuously regulating a connection flow of the transport layer and the congestion control of the transport layer;

suspending the ongoing transport layer connections during bad signal conditions;

resuming the ongoing transport layer connections after signal conditions improve; and

regulating the flow of the transport layer without hampering a user experience.
An apparatus of a user equipment (UE) for providing seamless connectivity in a communication network, comprising:

a transceiver; and

at least one processor coupled to the transceiver, wherein the at least one processor is configured to be operated according to one of the methods in claims 1 to 5.
An apparatus of a user equipment (UE) for providing seamless connectivity during mobility, comprising:

a transceiver; and

at least one processor coupled to the transceiver, wherein the at least one processor is configured to be operated according to one of the methods in claims 6 to 13.