The present disclosure relates to radio network communication. In one of its aspects, the disclosure presented herein concerns a method for assigning a value representing a length of a data packet to a field. The method is implemented in an apparatus. According to the method, a size of the data packet is determined. Based on the determined size of the data packet, the size of the field is set. The determined size of the data packet is then compared against a value threshold, and based on the comparison and based on the determined size of the data packet, a value representing the length of the data packet is calculated. The calculated value representing the length of the data packet is then assigned to the field.