wiki:SystemEngineering

4. System Engineering

4.1 WiMAX Standards

Ongoing WiMAX standards work is done by the WiMAX Forum. See, for example, the WiMAX Forum Technical Specifications

4.2 WiMAX Network Architecture

An technical overview of WiMAX network architecture is presented in WiMAX Forum Network Architecture Release 1.0 Version 4 - Stage 2: Architecture Tenets, Reference Model and Reference Points, including:

Fig 6-1) Network Reference Model

Fig 6-2) ASN Reference Model

4.3 GENI WiMAX Project Technical Overview

A technical overview of the GENI WiMAX project is presented in: GENI WiMAX Project: System Engineering Summary.

The GENI WiMAX project currently utilizes commercial NEC WiMAX equipment as the basis of its WiMAX campus deployment kit, including a Profile A Base Station and a separate ASN Gateway, joined by the R6 interface, per Figure 6-2, above. The R6 interface implementation is not fully standardized, and thus includes NEC-specific functions.

For the GENI WiMAX project, the WiMAX campus deployment kit provides the GENI Researcher with much flexibility:

The use of a Profile A Base Station with an exposed R6 interface enables the researcher to monitor and control the base station radio functions.
The ASN gateway utilizes some essential NEC code, but removes many high-level WiMAX functions (e.g., roaming) and allows the researcher to implement their own.
Finally, the ASN gateway includes slicing functions, to allow the base station and ASN gateway to be shared by multiple researchers at the same time.

Later in 2010, NEC will be updating their WiMAX equipment to utilize a Profile C Base Station, where some of the current ASN gateway functions are included in the Base station, and fully standardized R6 interface is exposed. When this occurs:

The current GENI-specific ASN gateway software will have to be modified, with an effort of at leat 2 MM.
The researcher will have diminished ability to monitor and control the base station radio functions.

4.4 GENI WiMAX Base Station Range and Capacity

Need to be able to estimate the expected range and capacity of a completed installation, and how this varies with antenna height, to guide each campus in their planning. Also, how this varies depending on the number of clients and their data rates.
Then, need to verify estiamtes with measurements at various sites.

Ivan Seskar: Have some data from Rutgers WINLAB site, and expect more when Rutgers Bush Campus site is in service. Can configure split between downstream and upstream. With 10MHz bandwidth, limited to approximately 20Mbps total. Have seen range approximately x10 of WiFi range. Have seen downstream of 2+Mbs at 2km combined with 7Mbs at short distances.

Ray Raychaudhuri on 3/16: Expect standard range information from NEC in 2+ weeks.

Max Ott on 3/16: Should consider planning tools seen at 3G trade shows, to estimate ranges.

Tony Michel on 3/30: Preparing plan to measure base station range and capacity at BBN Technologies site, starting with initial checkout.

Harry Mussman on 4/30: WiMAX Forum document on WiMAX Forum: "Mobile WiMAX – Part I: A Technical Overview and Performance Evaluation", March 2006 provides good information on range and capacity, including Dl and UL link budgets for a nominal case.

4.5 System Engineering Issues

No Issue Who Opened Resolved Resolution Note
4.1 "GENI Operator ID": Each WiMAX deployment requires an Operator ID (OpID), a parameter used within the base station and each client. Currently, Routgers WINLAB is using the Sprint/Clearwire ID, but this can only be temporary. We need to apply for and receive a "GENI Operator ID". Agosain 2/23/10 4/30/10 From IEEE: company_id is: 4451DB16, represented as a conventional 6-digit hexadecimal integer. Tutorials to help implement the use of the I.D. assignment Basis for the IEEE 802-2001 tutorial Per Seskar, apply at IEEE 802.16 site. Fee is $1650.
4.2 Range and capacity: Need to be able to estimate the expected range and capacity of a completed installation, and how this varies with antenna height, to guide each campus in their planning. Also, how this varies depending on the number of clients and their data rates. Then, need to verify at sites, Michel, Seskar, Rangarajan, Mussman 2/23/10 - - On 3/16: Expect standard range information from NEC in 2+ weeks. Ott on 3/16: Should consider planning tools seen at 3G trade shows, to estimate ranges. Michel on 3/10: Preparing emasurement plan. On 4/30: See WImAX Forum Technical Overivew document.
4.3 GPS receiver: NEC documentation shows a GPS receiver mounted along with the antenna, and connected to the NW INTFC on the IDU. It provides precise timing signals to the base station. Seskar, Mussman 2/23/10 2/23/10 Agreed to include in the kit, since total cost is likely to be less than $125, and it should be installed at the start. Next: Need to engineer active antenna and cable for up to 100m; see Kit Issues
4.4 "GENI PKI Certificate": If we want to do over-the-air provisioning to clients, we will require a PKI certifiacte signed by Verisign, that clients can verify (per Seskar). Michel, Agosain 2/23/10 - - Need to decide how GENI would use this; if worthwhile, then plan process to obtain one.
4.5 - - - - - -
Last modified 7 years ago Last modified on 07/27/12 11:25:47

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