4G-Ready Tools — 3GPP NAS
Productivity Support

In response to several customer requests to support the NAS (Non-Access-Stratum) protocol (3GPP TS 24.301), OSS Nokalva has developed a set of productivity enhancing tools that free customers from the task of writing software to create, process, debug and test NAS messages, which is particularly time consuming and error prone when dealing with changes in the 3GPP releases. Customers can focus instead on their core business.

OSS NAS Encoder/Decoder Library

The NAS Encoder/Decoder Library, available on Windows for C and C++, is a tool that facilitates the creation, encoding, decoding, and processing of messages conforming to the 3GPP Technical Specification 24.301.

The NAS Encoder/Decoder Library takes care of all of the unique aspects of NAS message serialization such as, required and optional information elements, bit-level format of each type of information element, bit order, half-octet order, and so on. A developer using the library works with a set of C structures or C++ classes provided with the library, and makes simple calls to encode and decode functions, as well as to other useful functions which are available.

Current users of OSS' ASN.1 C or C++ Tools will feel at home with the OSS NAS encoder/decoder API because both the API and the C structures and C++ classes are very similar to those used with protocols specified in ASN.1.

The NAS Encoder/Decoder Library API supports:

• Encoding and decoding NAS protocol data units
• Printing encoded or un-encoded NAS protocol data units in XML form
• Copying NAS protocol data units
• Comparing un-encoded or decoded NAS protocol data units

The OSS NAS Encoder/Decoder Library consists of a main run-time component and one or more plug-ins, each supporting a particular 3GPP release. An application using the NAS Encoder/Decoder Library can work with multiple versions of the NAS protocol (multiple 3GPP releases) through the same API.

OSS NAS-1Step

NAS-1Step is a Windows application that enables you to interactively create, view, and edit messages conforming to the 3GPP Technical Specification 24.301 (Non-Access-Stratum protocol). NAS-1Step consists of a main application and one or more plug-ins, each supporting a particular version of the NAS protocol.

NAS-1Step provides several functions such as:

• a text viewer that displays a description of the structure of NAS messages in a formal notation (ASN.1) and supports both syntax coloring and syntax-aware navigation; and
• a message viewer/editor able to load an encoded message from a file, decode the message, create a new message, make changes to a message, re-encode it, save it, and so on.

NAS-1Step is a useful tool for anyone working with the NAS protocol, from system designers to application developers and testers. It can be used for a range of activities, including displaying a NAS message in a collapsible tree-view, editing a NAS message, creating a set of NAS messages for testing purposes, and so on, and allows one to work simultaneously with messages belonging to multiple versions of the NAS protocol (multiple 3GPP releases).