diff --git a/include/osmocom/rspro/per_support.h b/include/osmocom/rspro/per_support.h
new file mode 100644
index 0000000..181fe24
--- /dev/null
+++ b/include/osmocom/rspro/per_support.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2005-2014 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_PER_SUPPORT_H_
+#define	_PER_SUPPORT_H_
+
+#include <asn_system.h>		/* Platform-specific types */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Pre-computed PER constraints.
+ */
+typedef const struct asn_per_constraint_s {
+	enum asn_per_constraint_flags {
+		APC_UNCONSTRAINED	= 0x0,	/* No PER visible constraints */
+		APC_SEMI_CONSTRAINED	= 0x1,	/* Constrained at "lb" */
+		APC_CONSTRAINED		= 0x2,	/* Fully constrained */
+		APC_EXTENSIBLE		= 0x4	/* May have extension */
+	} flags;
+	int  range_bits;		/* Full number of bits in the range */
+	int  effective_bits;		/* Effective bits */
+	int64_t lower_bound;		/* "lb" value */
+	int64_t upper_bound;		/* "ub" value */
+} asn_per_constraint_t;
+typedef const struct asn_per_constraints_s {
+	struct asn_per_constraint_s value;
+	struct asn_per_constraint_s size;
+	int (*value2code)(unsigned int value);
+	int (*code2value)(unsigned int code);
+} asn_per_constraints_t;
+
+/*
+ * This structure describes a position inside an incoming PER bit stream.
+ */
+typedef struct asn_per_data_s {
+  const uint8_t *buffer;  /* Pointer to the octet stream */
+		 size_t  nboff;   /* Bit offset to the meaningful bit */
+		 size_t  nbits;   /* Number of bits in the stream */
+		 size_t  moved;   /* Number of bits moved through this bit stream */
+  int (*refill)(struct asn_per_data_s *);
+  void *refill_key;
+} asn_per_data_t;
+
+/*
+ * Extract a small number of bits (<= 31) from the specified PER data pointer.
+ * This function returns -1 if the specified number of bits could not be
+ * extracted due to EOD or other conditions.
+ */
+int32_t per_get_few_bits(asn_per_data_t *per_data, int get_nbits);
+
+/* Undo the immediately preceeding "get_few_bits" operation */
+void per_get_undo(asn_per_data_t *per_data, int get_nbits);
+
+/*
+ * Extract a large number of bits from the specified PER data pointer.
+ * This function returns -1 if the specified number of bits could not be
+ * extracted due to EOD or other conditions.
+ */
+int per_get_many_bits(asn_per_data_t *pd, uint8_t *dst, int right_align,
+			int get_nbits);
+
+/*
+ * Get the length "n" from the Unaligned PER stream.
+ */
+ssize_t uper_get_length(asn_per_data_t *pd,
+			int effective_bound_bits,
+			int *repeat);
+
+ssize_t aper_get_length(asn_per_data_t *pd,
+						int range,
+						int effective_bound_bits,
+						int *repeat);
+
+/*
+ * Get the normally small length "n".
+ */
+ssize_t uper_get_nslength(asn_per_data_t *pd);
+ssize_t aper_get_nslength(asn_per_data_t *pd);
+
+/*
+ * Get the normally small non-negative whole number.
+ */
+ssize_t uper_get_nsnnwn(asn_per_data_t *pd);
+ssize_t aper_get_nsnnwn(asn_per_data_t *pd, int range);
+
+/* X.691-2008/11, #11.5.6 */
+int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *v, int nbits);
+
+/* Non-thread-safe debugging function, don't use it */
+char *per_data_string(asn_per_data_t *pd);
+
+/*
+ * This structure supports forming PER output.
+ */
+typedef struct asn_per_outp_s {
+	uint8_t *buffer;	/* Pointer into the (tmpspace) */
+	size_t nboff;		/* Bit offset to the meaningful bit */
+	size_t nbits;		/* Number of bits left in (tmpspace) */
+	uint8_t tmpspace[32];	/* Preliminary storage to hold data */
+	int (*outper)(const void *data, size_t size, void *op_key);
+	void *op_key;		/* Key for (outper) data callback */
+	size_t flushed_bytes;	/* Bytes already flushed through (outper) */
+} asn_per_outp_t;
+
+/* Output a small number of bits (<= 31) */
+int per_put_few_bits(asn_per_outp_t *per_data, uint32_t bits, int obits);
+
+/* Output a large number of bits */
+int per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int put_nbits);
+
+/* X.691-2008/11, #11.5 */
+int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits);
+int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits);
+
+/* Align the current bit position to octet bundary */
+int aper_put_align(asn_per_outp_t *po);
+int32_t aper_get_align(asn_per_data_t *pd);
+
+/*
+ * Put the length "n" to the Unaligned PER stream.
+ * This function returns the number of units which may be flushed
+ * in the next units saving iteration.
+ */
+ssize_t uper_put_length(asn_per_outp_t *po, size_t whole_length);
+
+ssize_t aper_put_length(asn_per_outp_t *po, int range, size_t length);
+
+/*
+ * Put the normally small length "n" to the Unaligned PER stream.
+ * Returns 0 or -1.
+ */
+int uper_put_nslength(asn_per_outp_t *po, size_t length);
+
+int aper_put_nslength(asn_per_outp_t *po, size_t length);
+
+/*
+ * Put the normally small non-negative whole number.
+ */
+int uper_put_nsnnwn(asn_per_outp_t *po, int n);
+
+int aper_put_nsnnwn(asn_per_outp_t *po, int range, int number);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _PER_SUPPORT_H_ */