diff --git a/rrlp-ephemeris/main.c b/rrlp-ephemeris/main.c
new file mode 100644
index 0000000..bb025a2
--- /dev/null
+++ b/rrlp-ephemeris/main.c
@@ -0,0 +1,99 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "gps.h"
+#include "ubx.h"
+#include "ubx-parse.h"
+#include "rrlp.h"
+
+static int
+do_ubx_read(struct gps_assist_data *gps, const char *filename)
+{
+	int rv, fd, i;
+	struct stat st;
+	void *buf;
+
+	/* Load file */
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	rv = fstat(fd, &st);
+	if (rv < 0) {
+		close(fd);
+		return -1;
+	}
+
+	buf = malloc(st.st_size);
+	if (!buf) {
+		close(fd);
+		return -1;
+	}
+
+	rv = read(fd, buf, st.st_size);
+	if (rv != st.st_size) {
+		free(buf);
+		close(fd);
+		return -1;
+	}
+
+	/* Parse each message */
+	for (i=0; i<st.st_size;) {
+		int rv;
+		rv = ubx_msg_dispatch(ubx_parse_dt, buf + i, st.st_size - i, gps);
+		if (rv < 0)
+			i++;	/* Invalid message: try one byte later */
+		else
+			i += rv;
+	}
+
+	/* Done */
+	free(buf);
+	close(fd);
+
+	return 0;
+}
+
+static int
+do_rrlp(struct gps_assist_data *gps)
+{
+	struct rrlp_assist_req ar;
+	void *pdus[64];
+	int len[64];
+	int i, rv;
+
+	char *test = "\x28\x00\x80\x10\x01\x32\x00\x19\x4F\x07\x15\x04";
+
+	rrlp_decode_assistance_request(&ar, test, 12);
+	printf("%08x %016llx\n", ar.req_elems, (long long unsigned) ar.eph_svs);
+
+	ar.req_elems = -1;
+	ar.eph_svs = -1LL;
+	rv = rrlp_gps_assist_pdus(gps, &ar, pdus, len, 64);
+	printf("%d\n", rv);
+	for (i=0; i<rv; i++) {
+		printf("%p %d\n", pdus[i], len[i]);
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct gps_assist_data gps;
+	int rv;
+
+	memset(&gps, 0x00, sizeof(gps));
+
+	rv = do_ubx_read(&gps, "data.ubx");
+	
+	rv = do_rrlp(&gps);
+
+	return 0;
+}
+