Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
4.1.1.4 Registration module
This module will take care of all the actions related to AAAC, mainly the registration phase. It will also
be used when a handover is required, but the Fast Handover cannot be used (inter-domain mobility,
unexpected network connectivity loss).
The behaviour of these components will be detailed in the next section.
4.1.1.5 Paging module
The module basically implements the IP paging engine, which is responsible for maintenance of the
signalling state machine as well as for keeping the mobile terminal’s state (active or dormant) updated.
Furthermore, an interface to the enhanced IPv6 protocol stack should allow suppression of Mobile IPv6
Binding Updates when being dormant as well as registration of the discovered Paging Agent with the
mobile terminal’s Home Agent. Since no enhanced dormant mode and paging support comes from
network device drivers within this project on IP paging specification yet, the basic functionality of the IP
Paging engine during a paging process with regard to the reception of paging related messages is to
handle reception of IP Paging Request messages through the different interfaces. Standard interaction
between IPv6 and device driver level supports the registration of IPv6 Solicited Node Multicast
Addresses, which is necessary for the reception of IP Paging messages through the shared medium
interfaces. For TD-CDMA, the same mechanism will be deployed here, which is addressing the mobile
terminal’s TD-CDMA Solicited Node Multicast Address from the AR/RG. This address is to be derived
out of the mobile terminal’s TD-CDMA interface’s IMEI.
The Dormant state watchdog is a function that should take the decision of when to enter the dormant
mode. Furthermore, related signalling is initiated from this function, sending a notification to the paging
engine when to enter dormant mode. For demonstration purposes, this function can be controlled
manually via the NCP to allow for entering the dormant mode and active mode on request. An
appropriate interface to the paging module will be implemented to allow for control from the NCP
through the MTNM. Optionally, automatic dormant state and active state transition might be supported in
the dormant state watchdog in future systems.
The behaviour of this Paging Module, its components and the relations to previously presented Moby
Dick architectural components will be detailed in the next section.
4.1.1.6 Enhanced IPv6 stack
The enhanced IPv6 stack will be based on the IPv6 stack of the Linux kernel 2.4.16, with the following
extensions:
• MIPL will be the patch 0.9.1 to the IPv6 stack, providing mobility extensions.
• SWAMP (Secure Wide-Area Mobility Package) combines IPSec and Mobile IPv6 implementations
in the Linux kernel by providing kernel patches and user space programs.
• DSCP marking software: will attribute a DSCP code to every outgoing IP packet, based on its type
(signalling or data of type x, y, z …). It will be a patch to the IPv6 stack.
• Fast handover functionality is provided by a ‘standalone’ kernel module (FHO module), including
interface to the IPv6 stack of the kernel (e.g., sending of ICMPv6 packets) and to Mobile IPv6 (e.g.,
Binding Update management in case of FHO). The first version includes a filtering functionality in
the IPv6 part of the kernel, in order to filter out WLAN Router Advertisements, which are received,
because the WLAN ad-hoc mode is deployed and all Access Routers are configured to the same
frequency channel. In later releases, this filtering functionality is moved to the WLAN driver; i.e., the
WLAN Device Driver is modified in order to provide this filtering functionality.
DSCP Marking Software
The DSCP marking software is composed of an application level module, which communicates with a
kernel level module, to provide a table matching DSCP codes with applications types (recognised by port
numbers, and any other pertinent information).
Thus every packet leaving the IPV6 stack will be marked with a DSCP code.
There will be one DSCP for the signalling packets (standard IPv6 signalling packets like ICMP, and
specific signalling packets, if any, used by mobility, AAAC, QoS).
There will be different DSCP for data packets, and the table provided by the application level module will
be used to attribute them to the proper IPv6 packets
The behaviour of these components will be detailed in the next section.
4.1.1.7 Network Device Driver
Radio Channel Manager
This module will act as a generic radio driver, giving high level interfaces to open / close connections,
send and receive IP packets, and get some feedback on the radio conditions.
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