This paper discusses the design of a single channel full-duplex wireless transceiver. The design uses a combination of RF and baseband techniques to achieve full-duplexing with minimal effect on link reliability. Experiments on real nodes show the fullduplex prototype achieves median performance that is within 8% of an ideal full-duplexing system. This paper presents Antenna Cancellation, a novel technique for self-interference cancellation. In conjunction with existing RF interference cancellation and digital baseband interference cancellation, antenna cancellation achieves the amount of self-interference cancellation required for full-duplex operation.The paper also discusses potential MAC and network gains with full-duplexing. It suggests ways in which a full-duplex system can solve some important problems with existing wireless systems including hidden terminals, loss of throughput due to congestion, and large end-to-end delays.

This paper presents a full duplex radio design using signal inversion and adaptive cancellation. Signal inversion uses a simple design based on a balanced/unbalanced (Balun) transformer. This new design, unlike prior work, supports wideband and high power systems. In theory, this new design has no limitation on bandwidth or power. In practice, we find that the signal inversion technique alone can cancel at least 45dB across a 40MHz bandwidth. Further, combining signal inversion cancellation with cancellation in the digital domain can reduce self-interference by up to 73dB for a 10MHz OFDM signal.This paper also presents a full duplex medium access control (MAC) design and evaluates it using a testbed of 5 prototype full duplex nodes. Full duplex reduces packet losses due to hidden terminals by up to 88%. Full duplex also mitigates unfair channel allocation in AP-based networks, increasing fairness from 0.85 to 0.98 while improving downlink throughput by 110% and uplink throughput by 15%. These experimental results show that a redesign of the wireless network stack to exploit full duplex capability can result in significant improvements in network performance.

Strategic product line breadth decisions evoke differential responses from the manufacturing and the marketing areas: manufacturing prefers keeping process disruptions to a minimum and, as a result, discourages product proliferation; however, marketing, in its attempt to match products to heterogeneous consumer needs and gain market share, emphasizes a broader product line. We systematically investigate the market benefits and cost disadvantages of broader product lines on a large sample of over 1,400 business units. Our results indicate significant market share benefits and increases in firms' profitability with broader product lines; moreover, widely held beliefs of increases in production costs are not empirically supported. American manufacturing firms may indeed be flexible enough to accommodate product variety without significant detrimental effects on costs.product line, market share, manufacturing costs, variety, profitability

Abstract:Clickstream data provides information about the sequence of pages or the path viewed by users as they navigate a web site. We show how path information can be categorized and modeled using a dynamic multinomial probit model of web browsing. We estimate this model using data from a major online bookseller. Our results show that the memory component of the model is crucial in accurately predicting a path. In comparison traditional multinomial probit and firstorder markov models predict paths poorly. These results suggest that paths may reflect a user's goals, which could be helpful in predicting future movements at a web site. One potential application of our model is to predict purchase conversion. We find that after only six viewings purchasers can be predicted with more than 40% accuracy, which is much better than the benchmark 7% purchase conversion prediction rate made without path information. This technique could be used to personalize web designs and product offerings based upon a user's path.

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