�ݺ�ߣ

Editor's Notes

• #8: Dynamic Bandwidth Management With other (a, an) transmissions it’s all or nothing – if the channel or one of the channels is busy then you cannot transmit. primary 20 MHz sub-channels is necessary to guarantee coexistence with legacy 802.11n devices two 80 MHz 802.11ac APs select the same 80 MHz channel bandwidth but one AP puts its primary 20 MHz channel within the lower 40 MHz and the other AP puts its primary 20 MHz channel within the upper 40 MHz. What this means is that 802.11n clients associated to the first AP can transmit 20 or 40 MHz as usual, at the same time as 802.11n clients associated to the second AP can transmit 20 or 40 MHz in parallel. What is new in 802.11ac is the ability for any 802.11ac client that sees that the whole 80 MHz as available to invoke a very high-speed mode and to transmit across the whole 80 MHz. ● Avoid channels with radar (if present). ● Uniformly spread the channel bandwidth used by each AP and preferably spread the AP’s primary 20 MHz channel too. ● Tend to avoid a channel that overlaps with other 20, 40, 80, 160, or 80+80 MHz APs nearby. ● Within an 80 MHz channel bandwidth (for example), decide whether to align primary 20 MHz channels with other APs or deliberately not to align primary channels. This is not a clear-cut choice: - If the primary channels are aligned, then virtual carrier sense works completely, yet all 20/40 MHz traffic (including broadcast, multicast, and data traffic to 802.11a/n devices) is sent in series. During these times, 40 or 60 MHz of bandwidth is unused. Still, if the clients are predominantly 802.11ac, then this is generally the best approach in terms of throughput and airtime fairness. - Conversely, if one AP’s primary channel is assigned to the lower 40 MHz and another AP’s channel is assigned to the upper 80 MHz, then 20/40 MHz traffic can be parallelized (as per Figure 5). If clients are predominantly 802.11a/802.11n, then this is the better choice. And when the whole 80 MHz is free, as measured by physical carrier sense and/or RTS/CTS with bandwidth indication, then 80 MHz communication between 802.11ac devices is still allowed. Certainly it is difficult to get the most out of 802.11ac without coordination of AP channel assignment, typically under the aegis of an effective centralized RRM algorithm.
• #9: Радиус круга для 60 Скорости примерно удваиваются соотношения радиусов не изменяются, но радиус покрытия для 80MHz примерно на 30% меньше радиуса для 40MHz (при той же MCS) 0Mbps (MCS9) есть 1/4 от радиуса круга, обеспечивающего 450Mbps (MCS7)
• #13: 802.11ас Wave2 и Wave1 используют одинаковый тип модуляции и ширину канала (* 160 Мгц каналы пока не используются) Пропускная способность 802.11ac Wave2 – менее 2Гбит/сек
• #34: Flow-based architecture allows for faster data processing verses packet processing because it does not need to look at every packet. Once initial flow is established the flow is kept in a flow table which makes look up much faster. Ten years of flow based innovation embedded in the AP for the first time. This is software story. Taking the slow path out of the hardware, tracking flows via a flow table verses looking up every packet. This fast paths traffic and increases performance and efficiency. SW advantage: Flow based forwarding has reduced per packet processing cost (only first packet of the flow is processed through the regular path, any subsequent packet of the flow directly directed) MIMO tests done with AP to AP mesh to maximize data rates. Also due to lack of Wave 2 clients at this point we are ready for 802.11ac Wave 2 clients +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
• #35: Make sure to point out the 2x2:2 capability which will allow you to migrate to Wave 2 if existing switches do not support PoE+ and you cannot upgrade both at once Key enhancements – relating to the hardware a few more things that can be highlighted: More encrypted clients per radio than before – now supporting up to 256 clients per radio (previous was 128) Hitless failover between the two Ethernet ports – the AP, assuming both ports are connected to PoE will stay up during loss of one link (great resiliency story, particularly for HC customers) 90,000pps – 20% more packet processing than our W1 AP 802.11ac Wave 2 – It is all about capacity Craig Mathias - The advent of MU-MIMO illustrates an interesting phenomenon in wireless LANs today: While the talk is usually all about throughput, the real issue is capacity. This means the emphasis going forward will not be on provisioning multi-gigabit throughput to a single client device. Instead, the goal will be to share all that wireless bandwidth to meet the needs of a diverse and rapidly increasing number of users, devices and applications. AP3935i/e – 802.11ac wave 2 AP. 4x4:4 indoor AP. Dual radio, 802.11ac a/b/g/n, 24.GHz & 5GHz, dual Ethernets, multi-user MIMO, beam forming. The AP3935 is a feature rich 802.11ac (Wave 2) and 802.11abgn indoor access point that delivers enterprise-grade performance and security. Designed to blend into the office, classroom, lecture hall, or large common spaces, the AP3935 is ideal for providing secure 802.11ac and 802.11abgn connectivity for high-density, mission critical environments such as schools, universities, hospitals, indoor arenas, and conference centers. The AP3965 is powered via 802.3at power-over-Ethernet (PoE+). The AP3935i/e is available in both internal and external antenna configurations. External configurations require professional installation. Use cases: Customers requiring high performance wireless solution Target Verticals: Mid-Large Enterprise, Higher Ed, K-12, Stadium/Convention Center Competitive: Cisco, HP-Aruba & Ruckus have announced Wave2 AP ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ AP3965i/e – 802.11ac wave 2 AP. 4x4:4 outdoor AP. Dual radio, 802.11ac a/b/g/n, 24.GHz & 5GHz, dual Ethernets, multi-user MIMO, beam forming. The AP3965i/e is a high-performance 802.11a/b/g/n/ac wave 2 outdoor access point that extends mobility beyond the brick-and-mortar. The outdoor access point is designed to operate in harsh environments such as warehouses, manufacturing plants, parks and stadiums. The AP3965 is powered via 802.3at power-over-Ethernet (PoE+). The AP39365i/e is available in both internal and external antenna configurations. External configurations require professional installation. Use cases: Customers requiring high performance outdoor wireless solution Target Verticals: Stadium/Convention Center, Manufacturing, Higher-Ed Competitive: No other vendor has made any announcement for Outdoor wave2 AP +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Wave 2 APs use Dual core 1.4GHz CPU vs Wave 1 Dual Core 800MHz
• #36: Saves on OPEX - Application Visibility Centralized or distributed AP model The AP/Appliance will be able to do N-Packet Mirroring to capture N-Packets and generate corresponding flow records for wireless user traffic. This is then forwarded to the Purview Engine. This eliminates the need for a CoreFlow product (still requires Purview and a Purview engine). How does it work? The AP will be able to do N-Packet Mirroring to capture N-Packets and generate corresponding flow records for wireless user traffic that are then sent to the IdentiFi appliance. This mirroring capability will be available for the AP3700 and AP3800 family of access points as a standard feature (free-of-charge), with each AP being able to track flows. This works for both the IdentiFi centralized and distributed AP configurations. Why do I care? All the value propositions from Purview now available to IdentiFi. This operates independent of the wired network to provide application visibility in heterogeneous network environments. Cloud friendly – extends application analytics to cloud deployments. Competitive advantage over centralized wireless appliance solutions since AP has intelligence to collect N-packet flows and send to the wireless core. The IdentiFi appliance aggregates the port mirrored traffic from the APs that it supports and then Purview does all the heavy lifting. This means all the visibility with zero impact to wireless performance. Simplifies installation by reducing the number of components – lowering TCO. Application visibility with the AP/appliance for better user/application visibility. All the visibility, with zero impact to wireless performance. This is a standard feature, with no additional charge.
• #37: HotSpot 2.0 functionality, also called Wi-Fi Certified Passpoint, is a new standard for public-access Wi-Fi that enables seamless and secure roaming between Cellular and Wi-Fi networks. This uses the 802.11u standard to enable secure (802.1x) and seamless authentication between the cellular network and the Wi-Fi network. This feature is supported on the AP3935i/e, AP3965i/e, AP3825i/e, AP3865e access points. This feature is perfect for stadiums, convention centers, public places and venues. HS 2.0 was developed by the Wi-Fi Alliance and the Wireless Broadband Association to enable seamless hand-off of traffic  without requiring additional user sign-on and authentication. Wi-Fi connections are faster and more battery-efficient than most mobile broadband options — and if you're travelling, even paying for Wi-Fi is often cheaper than roaming data. A hot spot (or hotspot) is a wireless LAN (local area network) node that provides Internet connection from a given location for users of devices with wireless connectivity.  Network discovery, registration, provisioning, and access processes are automated, so that the user does not have to go through them manually in order to connect and stay connected.