Note: Please see below about the ns-3.28.1 minor release update of ns-3.28.

ns-3.28 was released on 22 March 2018. ns-3.28 was updated to ns-3.28.1 on 16 August 2018. ns-3.28 and ns-3.28.1 feature the following additions over ns-3.27:

• IPv6 support for LTE: LTE UEs can now use IPv6 to send and receive traffic.
• TCP Pacing and TCP Low Priority (LP): Added TCP-LP congestion control, and added the core features of TCP Pacing.
• IP support for UAN: The UAN module now supports an IP stack, and added some examples for running raw, IPv4, IPv6, and 6LoWPAN over UAN.
• Extended addressing for LR-WPAN: Extended addressing mode is now supported.
• FIFO and TBF queue discs: Added a FIFO and Token Bucket Filter queue disc for the traffic control module.

Finally, the release includes numerous bug fixes and small improvements, listed in the RELEASE_NOTES.

• The latest ns-3.28.1 release source code can be downloaded from here
• What has changed since ns-3.27? Consult the changes page.
• What has changed since ns-3.28 for the minor release 3.28.1? Mainly assorted build system fixes for newer compilers (gcc-8) and libraries. Consult the changes page.
• The documentation is available in several formats from here.
• Errata containing late-breaking information about the release can be found here
• A patch to upgrade from the last release (ns-3.27) to ns-3.28 can be found here
• A patch to upgrade from ns-3.28 to the updated ns-3.28.1 can be found here