4 General

36.4653GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN) and Wireless Local Area Network (WLAN)Release 17TSXw interface user plane protocol

4.1 General aspects

The Xw user plane (Xw UP) protocol is located in the User Plane of the Radio Network layer over the Xw interface.

In LWA option, the Xw UP protocol is used to convey control information related to the user data flow management of E-RABs. The WT flow control feedback may support indication of successful transmission towards a UE, or successful delivery to the UE, as defined in TS 36.300 [2].

In LWIP option, the Xw UP protocol is used to convey control information related to the user data flow management of each UE. The WT flow control feedback may support indication of successful transmission towards a UE, as defined in TS 36.300 [2].

Each Xw UP protocol instance is associated to one E-RAB only.

This version of the present document defines the Xw UP protocol in the context of LTE-WLAN Aggregation and LWIP option, more specifically, for UE user data setup for LWIP operation or for Xw user data bearers setup for E-RABs configured with the LWA bearer option.

If configured, Xw UP protocol instances exist at the eNB and the WT between which the Xw user data bearers are setup.

In this version of the present document, Xw UP protocol data is conveyed by GTP-U protocol means, more specifically, by means of the “Xw RAN Container” GTP-U extension header as defined in TS 29.281 [3].