RoHC optimizations for burst losses

#This application is a 35 U.S.C. §371 national phase filing of International Application No. PCT/IB2014/063941, filed Aug. 15, 2014, the disclosure of which is incorporated herein by reference in its entirety.

#The present disclosure relates to Robust Header Compression (RoHC) and, in particular, RoHC optimizations to protect against context desynchronization resulting from a burst of lost packets.

#Robust Header Compression (RoHC) is used in 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) networks to minimize the amount of information transmitted over the air. RoHC is defined in Internet Engineering Task Force (IETF) Request for Comments (RFC) 3095, “RObust Header Compression (ROHC): Framework and four profiles: RTP, UDP, ESP, and uncompressed.” In particular, in 3GPP LTE, RoHC is utilized in the Packet Data Convergence Protocol (PDCP) layer to minimize the amount of information in Internet Protocol (IP)/User Datagram Protocol (UDP)/Real-Time Protocol (RTP) headers by taking advantage of the repetitive (correlated) nature of some of the fields in the IP/UDP/RTP headers. This is particularly beneficial for Voice over IP (VoIP) traffic where the amount of data being transmitted is typically much smaller than the size of the uncompressed IP/UDP/RTP headers. RoHC defines a “compressor,” which is the sender of RoHC compressed packets, and a “decompressor,” which is the receiver of the RoHC compressed packets.

#The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

#FIG. 1 illustrates a cellular communications network according to one embodiment of the present disclosure;

#FIG. 2 illustrates a radio node according to one embodiment of the present disclosure;

#The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

#Systems and methods are disclosed herein for optimizing Robust Header Compression (RoHC) to protect against context desynchronization resulting from a burst of lost packets. In this regard, FIG. 1 illustrates a cellular network 10 that includes a base station 12 and a wireless device 14 that operate to provide RoHC compression and decompression according to some embodiments of the present disclosure. In the embodiments described herein, the cellular network 10 is a 3rd Generation Partnership Projection (3GPP) Long Term Evolution (LTE) network and, as such, the base station 12 may be referred to as an enhanced Node B (eNB), and the wireless device 14 may be referred to as a User Equipment (UE). Further, the embodiments described herein specifically relate to RoHC within the Packet Data Convergence Protocol (PDCP) layer of the protocol stack of the wireless device 14 and/or the base station 12. Note however that the concepts disclosed herein are not limited to 3GPP LTE or RoHC within the PDCP layer of the LTE protocol stack. Rather, the RoHC techniques disclosed herein may be implemented in any suitable type of cellular communications network, any suitable wireless system, or any other communication system that utilizes RoHC, particularly over a lossy link.

#FIG. 2 illustrates a radio node 16 according to one embodiment of the present disclosure. The radio node 16 may be, e.g., the base station 12 or the wireless device 14 of FIG. 1. However, the radio node 16 is not limited thereto. As illustrated, the radio node 16 includes a protocol stack 18, which is implemented as a combination of hardware and software. The protocol stack 18 includes many layers including a Physical (PHY) layer 20, a Medium Access Control (MAC) layer 22, a Radio Link Control (RLC) layer 24, and a PDCP layer 26. The PHY layer 20 performs coding/decoding, modulation/demodulation, multi-antenna mapping, etc. The MAC layer 22 performs multiplexing of logical channels, hybrid Automatic Repeat Request (ARQ) retransmissions, and uplink and downlink scheduling. The RLC layer 24 performs functions such as segmentation/concatenation, retransmission handling, duplicate detection, and in-sequence delivery to higher layers. The RLC layer 24 includes one RLC entity per radio bearer configured for a UE.