diff --git a/include/common/hss_message.h b/include/common/hss_message.h
new file mode 100644
index 0000000..2835fcb
--- /dev/null
+++ b/include/common/hss_message.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2003-2018, Great Software Laboratory Pvt. Ltd.
+ * Copyright (c) 2017 Intel Corporation
+ * Copyright (c) 2019, Infosys Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __HSS_MSG_H_
+#define __HSS_MSG_H_
+
+#include "sec.h"
+
+/*Information needed for AIR*/
+enum e_BUF_HDR {
+	HSS_AIR_MSG,
+	HSS_AIA_MSG,
+	HSS_ULR_MSG,
+	HSS_ULA_MSG,
+	//NI Detach
+	HSS_CLR_MSG,
+	HSS_CLA_MSG,
+	//NI Detach
+	HSS_PURGE_MSG,
+	HSS_PURGE_RESP_MSG,
+};
+
+
+#define IMSI_STR_LEN 16
+/*AIR  - request. Struct is same for ULR*/
+struct hss_air_msg {
+	char imsi[IMSI_STR_LEN];
+	unsigned char  plmn_id[3];
+};
+
+/*AIA  - response*/
+struct hss_aia_msg {
+	struct RAND rand;
+	struct XRES xres;
+	struct AUTN autn;
+	struct KASME kasme;
+};
+
+#define HSS_MSISDN_LEN 10
+#define SPARE_LEN 52
+
+/*ULA  - response*/
+struct hss_ula_msg {
+	int subscription_state;
+	unsigned char msisdn[HSS_MSISDN_LEN];
+	unsigned char a_msisdn[HSS_MSISDN_LEN];
+	unsigned char spare[SPARE_LEN];
+};
+
+struct hss_clr_msg {
+	char origin_host;
+	char origin_realm;
+	char user_name;
+	unsigned char cancellation_type;
+};
+
+
+struct hss_pur_msg {
+	int ue_idx;
+	char imsi[IMSI_STR_LEN];
+};
+
+struct hss_req_msg {
+	enum e_BUF_HDR hdr;
+	int ue_idx;
+	union req_data {
+		struct hss_air_msg air;
+	}data;
+};
+
+struct hss_resp_msg {
+	enum e_BUF_HDR hdr;
+	int ue_idx;
+	int result;
+	union resp_data {
+		struct hss_aia_msg aia;
+		struct hss_ula_msg ula;
+		struct hss_clr_msg clr;
+	}data;
+};
+
+#define HSS_RCV_BUF_SIZE 128
+#define HSS_REQ_MSG_SIZE sizeof(struct hss_req_msg)
+#define HSS_RESP_MSG_SIZE sizeof(struct hss_resp_msg)
+
+#endif /*__STAGE6_S6A_MSG_H_*/
+