This paper examines, via simulation, the performance of an 802.11e MAC over an 802.11g PHY operating in DSSS-OFDM mode. The DSSS-OFDM scheme provides data rates of up to 54Mb/s as well as interoperability with 802.11b nodes. Due to the widespread use of 802.11b nodes, such interoperability is an important consideration. This paper involves a study of the number of simultaneous bidirectional G.711 VoIP calls that can be supported by such a WLAN. The results show that this mode of operation introduces a very significant overhead. The actual number of calls that can be carried is limited to 12 when using the 24Mb/s data rate and 13 when using either the 36Mb/s or 54Mb/s rates.
Related white papers
Statoil Fires Up Connection on the Move With Wireless Hotspots
Statoil is Scandinavia's leading upstream and downstream oil company. Statoil operated a Frame Relay-based Wide Area Network and switched to an infrastructure based on Internet Protocol (IP) in a bid...
Exploiting Medium Access Diversity in Rate Adaptive Wireless LANs
Recent years have seen the growing popularity of multi-rate wireless network devices (e.g., 802.11a cards) that can exploit variations in channel conditions and improve overall network throughput. Concurrently, rate adaptation...
Crescent Girls' School Unwires Secondary Education With Pervasive Mobile Computing
Crescent Girls' School in Singapore is 1400-student secondary school that has integrated learning technologies into its curriculum in many innovative ways. Crescent Girls' School, through its m-Learning@Crescent e-learning initiative deployed...
Asymptotic Performance of Transmit Diversity Via OFDM for Multipath Channels
Many wireless systems exploit transmit diversity for more reliable detection of signals at the receiver. To accomplish this, coding is spread across multiple transmit antennas. An example of this is...
Performance Analysis of Diversity Combining Method for OFDM Blind Carrier Synchronization
Orthogonal Frequency Division Multiplexing (OFDM) communications transform frequency selective channels into multiple low rate subchannels robust against frequency selective fading. Carrier Frequency Offset (CFO) between transmitter and receiver local oscillators...
New Methods and Solutions Based on Contactless Smart-Card (CSC) for Customer Servicing and CRM Development in a Muti-Modal / Inter-Modal Transport Environment
This paper deals with customer identification and access control to personalized services in the context of multimodal transport services and in-car telematics services. This paper presents a vision or concept...
Cisco and Intel Present: How the Latest 802.11i Wireless Security Standards Will Help Secure Your Business
This webcast explains how the latest WiFi Alliance security standard 802.11i, also known as WPA2, makes wireless networks as secure as wired. This seminar explains some of the key features...


