Multi-path wireless communication

Abstract

A client and a server communicate over multiple wireless access paths each using a different wireless network. A method performed at the server comprises receiving at the server a signal from the client via one of multiple wireless access paths, the signal comprising a transport layer portion including a transport layer identifier, the transport layer identifier providing an indication of a wireless access path, a network layer portion, and a data portion, determining from the transport layer identifier, a destination of at least a subset of the signals from the wireless access path indicatedby the transport layer identifier, and routing the signal to the destination. If a flow is diverted to travel via a different route, then there must be some mechanism to ensure that the signal arrivesat its intended destination. Preferably, a Multi-path Transport Control Protocol (MPTCP) is used as the transport layer protocol. MPTCP binds one or multiple TCP subflows into one logical connectionbetween a content data server and a user client application. In the client device, a network policy module specifies what physical paths can be accessed and whether they are used symmetrically for ACKdelivery (marker [a]). Signals that are diverted such that they are sent between these devices on a different access path to that originally envisaged, need to be rerouted within the receiving devicesuch that they arrive at the correct socket and can be processed by the appropriate receiver. To implement the WiFi uplink over LTE uplink policy, a client pre-routing function (marker [b]) modifiesthe source / destination IP addresses of the uplink TCP packets prior to passing them to the network so that the network can then transparently carry out the desired traffic routing. On the server side,a server pre-routing function (marker [c]) modifies the destination IP addresses of all TCP ACKs such that the IP layer subsequently ensures delivery to the correct TCP state machines of the server.The server establishes the TCP ACK-to-TCP socket mapping during TCP connection setup and maintains its state by monitoring TCP traffic (marker [d]).

Description

technical field [0001] The field of the invention relates to wireless communication networks, and more particularly to networks having multiple wireless paths between a client and a server. Background technique [0002] Modern mobile devices, such as smartphones and tablets, have ever-increasing data requirements. They also typically support multi-technology multi-band networks and are often equipped with multiple LTE, HSPA, WiFi transceivers that can operate in multiple licensed and unlicensed bands. Additionally, allocation of new (shared) frequency bands can be expected in the near future. [0003] The ability to communicate over multiple radio interfaces can be exploited by implementing multipath data transfer over parallel wireless links (paths). Using multiple resources to deliver data can provide significant increases in throughput and link reliability as well as lower latency compared to traditional single-path paradigms. [0004] However, communicating over diffe...

AI Technical Summary

Problems solved by technology

For example, IEEE WiFi networks are often characterized by high peak rates, but are less efficient with small packets and have limited coverage due to low transmit power constraints

However, more critically, their effective throughput decreases with the variation of the total load due to frequent packet collisions, since communication under WiFi is performed on a contention-based media access scheme, which means that collisions will occur

For example, a TCP acknowledgment (ACK) on the uplink can cause approximately 30% degradation of the TCP payload flow on the downlink due to uplink-downlink collisions

[0006] On the other hand, 3GPP HSPA / LTE networks are characterized by ubiquitous coverage, high spectral efficiency, and scheduled (collision-free) medium access, although they use relatively smaller bandwidth than WiFi and typically experience longer end-to-end packet delivery delay

Images