stds-80220-requirements: contribution to 802.20 requirements document
Contribution to revision three:
Section 4.22, Quality of Service and The MAC
The System MUST support grouping of transmission properties into service
classes, so enabling upper layer entities and external applications can
be mapped to request transmission intervals capable of exhibiting
desired QoS parameters in a globally consistent manner. The QoS
sub-system will adopt a "Matched Criteria" and "Enforcement"
methodology, such that packets and flows characteristics being fed into
the system that match a pre-defined rule set will be enforced
accordingly.
Section 4.22.1, Cos/QoS Matched-Criteria
The system must be able to fingerprint ingress traffic based upon the
matched criterias as defined below. The system should be designed such
that one or multiple (as many as 8) matched criterias can be placed into
an enforcement policy.
Section 4.22.1.1, Protocol Field Mapping
Flexible bit-based masking of multiple fields at every layer MUST be
made available for purposes of identifying packets. These matched
criterions include but are not limited to:
L4 Protocol field (UDP/TCP port number)
L4 Header length
L4 TCP flags
L4 TCP options (if present)
L3 Protocol field
L3 Source address/network
L3 Destination address/network
L3 Total length
L3 Fragmentation (Initial 4 bits of two-byte field)
L3 DiffServe/TOS field (to include ECN)
L2 Ethernet hardware address (two groups, 3 bytes each / entire 6 byte
address)
L2 Ethertype
L2 802.1Q/p
L7 Unencrypted HTTP version 1.x protocol fingerprinting (desired)
Section 4.22.1.2, Hardware Mapping
The system should be able to differentiate policies bound to groups of
Mobile Stations.
Section 4.22.1.3, Other (NEW)
Additional criterion must be evaluated by both Mobile and Base Station:
Ingress Flow rates (source/destination IP address and port numbers)
Ingress Aggregate data rates
Data tonnage-based L3 resource usage quotas
Airtime utilization-based PHY resource usage quotas
Section 4.22.2, CoS/QoS Enforcement
The following "ENFORCEMENT" actions will be available to handle
matched-criteria.
Section 4.22.2.1, Inter-packet delay variation (DELETE)
Section 4.22.2.2, One-way, round-trip delay (DELETE)
Section 4.22.2.3, Prioritization
The system must make available no less than eight node-based priority
queues. Mobile Nodes provisioned with the highest priority will have a
more heavily weighted probability for service. Conversely, Mobile Nodes
provisioned for the lowest available priority wll only be given service
if PHY/MAC resources are available.
Section 4.22.2.4, Error Correction
Higher coding / ARQ: The system must have the ability to increase the
probability of a successful packet transmission.
Section 4.22.2.5, Queuing
The system must make available no less than sixteen flow-based
operator-defined priority queues. Latency, priority, jitter,
error-correction, maximum throughput and queue depths will be considered
for the development of these queues.
Section 4.22.2.6, Suppression
Hard drop: The system MUST be able to block matched packet prior to
transmission over either uplink or downlink air interfaces.
Section 4.22.2.7, Aggregate Bandwidth Partitioning (NEW)
Partitioning: The system must allow for partitioning of the aggregate
bandwidth pipe. While the base station equipment is operating in a
resource under-utilized state, any unused bandwidth must be made
available to Mobile Stations requiring the resources regardless of which
partition the CPE has been allocationed (soft partitioning).
Section 4.22.2.8, Interface Binding (NEW)
Policy enforcement should be implemented on CPE packet input and base
station packet output, as applicable, such that PHY/MAC resources are
not unnecessarily utilized. Packet-queuing and queue-depths must be
configurable for both base station WAN ingress and mobile station LAN
ingress interfaces. Queue depth configuration will be available in
increments of datagrams and time.
Section 4.22.2.9, Packet Mangling (NEW)
Packet/Frame manipulation: IP Diffserve/TOS field modification to any
predetermined operator value. For customer redirection, the destination
address of IP packets should be modified to any predetermined operator
value (captive portal, acceptable usage policy violation, etc). For
bridged environments, the system MUST possess the ability to modify the
802.1p priority field to any predetermined operator specified value.
Marking will take place at either the Mobile or Base Station, as
appropriate.
Section 4.22.2.10, Resource Scheduling (NEW)
PHY/MAC resource scheduling: System must possess ability to starve a
Mobile Station's resource allocation of PHY resources for an operator
specified time value, with resolution of 10ms increments.
Section 4.22.2.11, Rate-limiting (NEW)
Throughput rate limiting: System must allow for an endpoint node egress
to be rate limited in increments of 8kbs, with classifications for peak
and best-effort minimum resource allocation. During under-load
conditions, unused bandwidth must be made available to satisfy active
CPE bursting requirements.
Section 4.22.3, ARQ/Retransmission
The system must not induce more than 10ms latency for the retransmission
of a lost block of data. Dropped data segments should not hinder the
timely delivery of any subsequent datagrams (successfully reconstructed
datagrams should not wait in queue for the reconstruction of datagrams
that encountered dropped packets and are waiting to be re-sent).
Section 4.22.4, MAC Error Performance
The packet error rate (PER), after application of appropriate error
correction mechanism (e.g., forward error correction) but before ARQ,
delivered by the PHY layer to the MAC layer, must meet a requirement of
1% for tests conducted with 512 byte packets. The ratio of MAC protocol
services becoming available to unavailable must e 99.9% of the time,
provided the system and radios receive adequate power 100% of the time.
Section 4.22.5, Latency
Delays are derived from filters, frame alignment, time-slot interchange,
switch processing, propagation, packetization, forward error correction,
interleaving, contention/access, queue depths, or any other lapse in
time associated with transmission on the wireless medium. Synchronous
services, such as TCP applicaitons or VoIP require short, predictable
(i.e., constant) delay.
Section 4.22.5.1, End to End Latency
The MAC protocol must guarantee periodic access to the medium. PHY
resources dedicated for this function must not impact system goodput
capacity by more than 5%.
The contention access mechanism must not incur more than 15 msec system
delay, excluding the time the system is in a blocking state due to
over-capacity on the contention medium.
The first packet pass-through initiated by the subscriber, while the
mobile station is not in an active state, must incur less than 20 msec
one-way delay (inclusive of contention/access latencies).
The first packet pass-through initiated by the base station, while the
mobile station is not in an active state, must incur less than 20 msec
one-way delay, exclusive of regular active-state latencies.
64-byte packet pass-through must comply with a maximum round trip delay
of less than 20 msec, exclusive of input or output queue depth and
contention delay.
Section 4.22.5.2, End to End Latency Variation
Contention/access delays must remain constant, regardless of the number
of mobile stations already in an active state.
Section 4.22.6, Protocol Support (May require being broken down and
placed in multiple or new sections)
The system must support transport of variable length Internet Protocol
packets ranging from 46 to 1500 bytes. Segmentation and re-assembly
techniques may be used to arrange traffic on the medium.
The system must be able to support the optional suppression of any and
all L2 and L3 broadcasts, as applicable, at the Mobile or Base Stations
(see QoS section Matched Criteria).
The system must be capable of passing IPSec traffic (RFC2401), and as
such, be capable of functioning wth off-the-shelf VPN software and
hardware. The system must be capable of passing additional
encapsulation protocol types: GRE (RFC1701), L2TP (RFC2261), PPTP
(RFC2637).
Section 4.22.7, Addressing
For external Mobile Stations with Ethernet adapters, the system must be
capable of limiting the number of customer hardware MAC addresses
learned by the Mobile Station. This value must be configurable per
Mobile Station and in real-time without reboots.
Section 4.22.8, Support/Optimization for TCP/IP
The MAC protocol should provide an efficient method of TCP
acknowledgement transmission in such a way that does not hinder the
ability of a system to deliver peak per-user capacity.
In the event the Base Station terminates the last-mile IP session, the
TCP stack must support Explicit Congestion Notification as defined by
RFC3168. At no time will the Base Station block packets classified with
the ECN flag.
Section 4.22.9, MAC Complexity Issues
Section 4.22.10, Additional IP Offerings
Section 4.23, Layer 3+ Support
The system must support both IPv4 and IPv6.
Section 4.23.1, OA&M Support
The following values must be made available in real-time with redisplay
intervals of no less than 1000 msecs, with the option to be displayed in
both cumulative and delta modes:
a) Aggregate base station bytes served at each coding/modulation
configuration
b) Correctable and uncorrectable block errors
c) Identity of specific Mobile Stations which exhibit a higher than
average packet error rate
d) PHY/MAC/NET based usage consumption statistics per Mobile Station
e) Successful and failed service requests for both up and downlink
directions
f) Unique number of active Mobile Stations, as well as which specific
stations are active, for both up and downlink directions
g) Number of ungraceful session disconnections